NHS England FHIR Implementation Guide (deprecated)

NHSDigital-MessageHeader

Conformance url	FHIR Module	Maturity Level
https://fhir.nhs.uk/StructureDefinition/NHSDigital-MessageHeader	Implementation Support	trial-use

with MessageHeader

MessageHeader	I		MessageHeader	Element Id MessageHeader Short description A resource that describes a message that is exchanged between systems Definition The header for a FHIR Message exchange that is either requesting or responding to an action. The reference(s) that are the subject of the action as well as other information related to the action are typically transmitted in a bundle in which the MessageHeader resource instance is the first resource in the bundle. Messaging middleware systems are expected to use this `MessageHeader` resource to route, deliver and handle messages correctly. This profile is not tied to any specific transport/API requirement or clinical requirement. Intermediaries are not expected to perform detailed routing on clinical content. Some clinical information will be required for routing purposes and this will be held within `eventCoding` and `reason` sections as discussed in the Message Event section below. In circumstances where more detailed information is required for routing this MUST be carried in the relevant FHIR Resource in the payload only. For example, document types should be recorded in FHIR `DocumentReference.type` and health service/specialty type can be recorded in FHIR `Encounter.serviceType` or `DocumentReference.context.practiceSetting`. Systems involved in NHSDigital/UKCore messaging are expected to support this profile only, extensions or derived profiles are permitted but they may only have limited (internal) scope and will not be supported outside of this scope (e.g. externally). This resource SHOULD NOT be profiled to further define the contents of the resources and FHIR MessageDefinition MUST be used instead. Comments identifiers and message timings FHIR messages have two identifiers: the messageIdentifier of the Message (`Bundle.identifier`) and a messageId (`Bundle.id`) which is used in each transport channel . The messageId should be unique within a each message channel/stream. Whenever a message is resent, the messageIdentifier of the Bundle remains the same, but the messageId may change. The response message has its own unique messageIdentifier, the messageIdentifier of the request message can be referenced in the MessageHeader.response.identifier element. The `Bundle.identifier`, the messageIdentifier, MUST have a UUID value. Systems may chose to map X-Request-ID header to the `Bundle.id`, messageId. If both are supplied to a `$process-messge` endpoint it is recommended they hold the same values. MessageHeader can hold previous and extra messageId's in the {{link:https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-messageId}} Local Part/Addressing (sender and/or destination.receiver) When exchanging messages between organisations, local references SHOULD NOT be used for `sender` and `destination.receiver` references. Local references can make use of the Extension {{link:https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-LocalPart}}. Messages between Organisations should be directed to the Organisation. The receiving organisation will take responsibility for delivering to the local address. Sending organisations are not expected to be able to deliver to local entities in another organisation/domain/facility. This concept is similar to email addresses `local-part@domain` and also HL7 version 2 combination of `Sending/Receiving Application \| Sennding/Receiving Facility` in the MSH segment. In the example below, the destination is a clinic (A99968) which part of NHS Trust (RBA). Note also the destination endpoint is for the NHS Trust, who will route the message as required. `"destination": [ { "endpoint": "urn:nhs-uk:addressing:ods:RBA", "receiver": { "extension": [ { "url": "https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-LocalPart", "valueReference": { "identifier": { "system": "https://fhir.nhs.uk/Id/ods-organization-code", "value": "A99968" } } } ], "identifier": { "system": "https://fhir.nhs.uk/Id/ods-organization-code", "value": "RBA" }, "display": "TAUNTON AND SOMERSET NHS FOUNDATION TRUST" } } ],` example - Prescription, Pharmacy known {{render:nominatedPharmacy}} In the example below, the prescriber Taunton and Somerset Foundation Trust (RBA), is sending a message to The Simple Pharmacy (VNE51). The `destination.receiver` and `sender` are references to these organisations. This message is to be sent via the Electronic Prescription Service, the http address of EPS is held in `destination.endpoint`. Replies to this message can only be received by MESH and the `source.endpoint` is the MESH address of the sending organisation. "destination": [ { "endpoint": "https://sandbox.api.service.nhs.uk/electronic-prescriptions/$post-message", "receiver": { "identifier": { "system": "https://fhir.nhs.uk/Id/ods-organization-code", "value": "VNE51" }, "display": "The Simple Pharmacy" } } ], "sender": { "identifier": { "extension": [ { "url": "https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-LocalPart", "valueReference": { "identifier": { "system": "https://fhir.nhs.uk/Id/ods-organization-code", "value": "A99968" } } } ], "system": "https://fhir.nhs.uk/Id/ods-organization-code", "value": "RBA" }, "display": "TAUNTON AND SOMERSET NHS FOUNDATION TRUST" }, "source": { "endpoint": "urn:nhs-uk:addressing:ods:RBA" } EPS will now send this message to the pharmacy. This message is collected by the pharmacy using MESH and so the `destination.endpoint` is now the MESH address of the pharmacy. Replies to this message are sent to EPS and so the `source.endpoint` is now the http address of the EPS $process-message endpoint. "destination": [ { "endpoint": "urn:nhs-uk:addressing:ods:VNE51", "receiver": { "identifier": { "system": "https://fhir.nhs.uk/Id/ods-organization-code", "value": "VNE51" }, "display": "The Simple Pharmacy" } } ], "sender": { "extension": [ { "url": "https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-LocalPart", "valueReference": { "identifier": { "system": "https://fhir.nhs.uk/Id/ods-organization-code", "value": "A99968" } } } ], "identifier": { "system": "https://fhir.nhs.uk/Id/ods-organization-code", "value": "RBA" }, "display": "TAUNTON AND SOMERSET NHS FOUNDATION TRUST" }, "source": { "endpoint": "https://sandbox.api.service.nhs.uk/electronic-prescriptions/$post-message" } example - Prescription, Pharmacy not known {{render:noNominatedPharmacy}} In this example the destination is not known and the message is sent to NHS Digital (X26). "destination": [ { "endpoint": "https://sandbox.api.service.nhs.uk/electronic-prescriptions/$post-message", "receiver": { {{render:messageIDs}} In addition, a FHIR Message Bundle has two important timestamps: The time of sending the message is captured in the timestamp element The last time the message was updated (e.g. by storing or modification) is captured in the meta.lastUpdated element. ```json { "resourceType": "Bundle", "id": "884cfa4f-7a56-4be5-9592-783ef4f3992a", "meta": { "lastUpdated": "2020-11-02T01:43:30+00:00" }, "identifier": { "system": "https://tools.ietf.org/html/rfc4122", "value": "ad945a29-85f8-439a-b590-6789719adc16" }, "type": "message", "timestamp": "2020-11-02T01:43:30+00:00", "entry": [ { "fullUrl": "urn:uuid:311316d3-1de0-4f7c-8109-c950ead1c717", "resource": { "resourceType": "MessageHeader", "extension": [ { "url": "https://fhir.nhs.uk/StructureDefinition/Extension-Spine-MessageHeader-messageId", "valueIdentifier": { "system": "https://fhir.nhs.uk/Id/prescription-order-number", "value": "DC2C66-A1B2C3-23407B" } } ] From (source and sender) and To (destination) The From is contained in both the `sender` and `source` elements and the To is contained in the `destination` array. One source, sender and at least one destination MUST be present. Messages may be sent over multiple transmission legs (i.e. the first leg uses http and the second MESH). The contents of elements SHOULD reflect the current leg only. destination.endpoint source.endpoint MessageHeader.extension(messageId) Endpoints MUST point to valid endpoint uri's on each leg of the messages journey, they may not refer to inaccessible endpoints on other legs. See also the destination section below. Data Type MessageHeader Constraints dom-2:If the resource is contained in another resource, it SHALL NOT contain nested Resources `contained.contained.empty()` dom-4:If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated `contained.meta.versionId.empty() and contained.meta.lastUpdated.empty()` dom-3:If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource or SHALL refer to the containing resource `contained.where((('#'+id in (%resource.descendants().reference \| %resource.descendants().as(canonical) \| %resource.descendants().as(uri) \| %resource.descendants().as(url))) or descendants().where(reference = '#').exists() or descendants().where(as(canonical) = '#').exists() or descendants().where(as(canonical) = '#').exists()).not()).trace('unmatched', id).empty()` dom-6:A resource should have narrative for robust management text.`div`.exists() dom-5:If a resource is contained in another resource, it SHALL NOT have a security label `contained.meta.security.empty()` nhsd-11:replacementOf extension is required for update messages `event.code.where(substring($this.length()-6) = 'update').exists().not() or (event.code.where(substring($this.length()-6) = 'update').exists() and extension('https://fhir.nhs.uk/StructureDefinition/Extension-replacementOf').exists())` Mappings rim:Entity. Role, or Act v2:MSH / MSA / ERR rim:Message
extension	I	0..*	Extension	Element Id MessageHeader.extension Short description Additional content defined by implementations Alternate names extensions, user content Definition May be used to represent additional information that is not part of the basic definition of the resource. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Comments There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone. Data Type Extension Sliced: Unordered, Open, by url(Value) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ext-1:Must have either extensions or value[x], not both `extension.exists() != value.exists()` Mappings rim:n/a rim:N/A
messageHeaderInstruction	I	0..*	Extension(Coding)	There are no (further) constraints on this element Element Id MessageHeader.extension:messageHeaderInstruction Short description An extension to carry a specific instruction for receivers of the message. Alternate names extensions, user content Definition An extension to carry a specific instruction for receivers of the message. Comments There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone. Data Type Extension(Coding) Extension URL https://fhir.hl7.org.uk/StructureDefinition/Extension-UKCore-MessageHeaderInstruction Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ext-1:Must have either extensions or value[x], not both `extension.exists() != value.exists()` Mappings rim:n/a rim:N/A
replacementOf	S I	0..1	Extension(Identifier)	Element Id MessageHeader.extension:replacementOf Short description Optional Extensions Element Alternate names extensions, user content Definition If the message is an update or replaceOf a previous message, then this extension should reference the replaced FHIR Message (Bundle.identifier). `"extension": [ { "url": "https://fhir.nhs.uk/StructureDefinition/Extension-replacementOf", "valueIdentifier": { "system": "https://tools.ietf.org/html/rfc4122", "value": "334a3195-1f6c-497a-8efe-d272ca9c4e38" } } ],` Comments There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone. Data Type Extension(Identifier) Extension URL https://fhir.nhs.uk/StructureDefinition/Extension-replacementOf Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ext-1:Must have either extensions or value[x], not both `extension.exists() != value.exists()` Mappings rim:n/a rim:N/A
event[x]	S Σ	1..1	Binding	Element Id MessageHeader.event[x] Short description Code for the event this message represents or link to event definition Definition The main message type is held in the mandatory `eventCoding` section which can be subdivided by the optional `reason` codes. Every code MUST have a corresponding `MessageDefinition`. For example the event code `dispense-notification` has a MessageDefintion of https://fhir.nhs.uk/MessageDefinition/pharmacy-dispense. This definition lists the profiles and cardinality of the resources in the message. `eventCoding` and MessageDefintion define the structure of the message. `"eventCoding": { "system": "https://fhir.nhs.uk/CodeSystem/message-event", "code": "dispense-notification", "display": "Dispense Notification" }` Requirements Drives the behavior associated with this message. Comments The time of the event will be found in the focus resource. The time of the message will be found in Bundle.timestamp. Binding Message event NHSMessageEvents (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a w5:FiveWs.what[x] v2:MSH-9.2 rim:./payload[classCode="CACT" and moodCode="EVN" and isNormalAct()]/code[isNormalDatatype()]/code
eventCoding			Coding	Data Type Coding
system	Σ	1..1	uri	There are no (further) constraints on this element Element Id MessageHeader.event[x].system Short description Identity of the terminology system Definition The identification of the code system that defines the meaning of the symbol in the code. Requirements Need to be unambiguous about the source of the definition of the symbol. Comments The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should reference to some definition that establishes the system clearly and unambiguously. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE.3 rim:./codeSystem orim:*fhir:Coding.system rdfs:subPropertyOf dt:CDCoding.codeSystem
version	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.event[x].version Short description Version of the system - if relevant Definition The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured, and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged. Comments Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE.7 rim:./codeSystemVersion orim:*fhir:Coding.version rdfs:subPropertyOf dt:CDCoding.codeSystemVersion
code	Σ	1..1	code	There are no (further) constraints on this element Element Id MessageHeader.event[x].code Short description Symbol in syntax defined by the system Definition A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination). Requirements Need to refer to a particular code in the system. Comments Note that FHIR strings SHALL NOT exceed 1MB in size Data Type code Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE.1 rim:./code orim:*fhir:Coding.code rdfs:subPropertyOf dt:CDCoding.code
display	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.event[x].display Short description Representation defined by the system Definition A representation of the meaning of the code in the system, following the rules of the system. Requirements Need to be able to carry a human-readable meaning of the code for readers that do not know the system. Comments Note that FHIR strings SHALL NOT exceed 1MB in size Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE.2 - but note this is not well followed rim:CV.displayName orim:*fhir:Coding.display rdfs:subPropertyOf dt:CDCoding.displayName
userSelected	Σ	0..1	boolean	There are no (further) constraints on this element Element Id MessageHeader.event[x].userSelected Short description If this coding was chosen directly by the user Definition Indicates that this coding was chosen by a user directly - e.g. off a pick list of available items (codes or displays). Requirements This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing. Comments Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely. Data Type boolean Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:Sometimes implied by being first rim:CD.codingRationale orim:fhir:Coding.userSelected fhir:mapsTo dt:CDCoding.codingRationale. fhir:Coding.userSelected fhir:hasMap fhir:Coding.userSelected.map. fhir:Coding.userSelected.map a fhir:Map; fhir:target dt:CDCoding.codingRationale. fhir:Coding.userSelected\#true a [ fhir:source "true"; fhir:target dt:CDCoding.codingRationale\#O ]
destination	S Σ	0..*	BackboneElement	Element Id MessageHeader.destination Short description Message destination application(s) Definition Lists all the destinations where message is be delivered to. The recipient of a message takes the responsibility of delivering to all the `destination.endpoint`s. Similarly the sender MUST NOT include destination's the recipient can not deliver to, these destinations MUST be removed from the message. Additional rules for endpoint can be found in the source section below. Requirements Indicates where message is to be sent for routing purposes. Allows verification of "am I the intended recipient". `"destination": [ { "endpoint": "urn:nhs-uk:addressing:mesh:Y90638OT002", "receiver": { "identifier": { "system": "https://fhir.nhs.uk/Id/ods-organization-code", "value": "Y9063" } } } ]` Comments There SHOULD be at least one destination, but in some circumstances, the source system is unaware of any particular destination system. Data Type BackboneElement Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a w5:FiveWs.subject[x] rim:./communicationFunction[typeCode="RCV"] w5:FiveWs.subject
name	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.destination.name Short description Name of system Definition Human-readable name for the target system. Requirements May be used for routing of response and/or to support audit. Comments Note that FHIR strings SHALL NOT exceed 1MB in size Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:MSH-5 rim:unique(./entity[determinerCode="INST" and (classCode=("DEV", "PSN", "ORG"]/name[type='ST' and isNormalDatatype()])
target	Σ I	0..1	Reference(UK Core Device)	There are no (further) constraints on this element Element Id MessageHeader.destination.target Short description Particular delivery destination within the destination Definition Identifies the target end system in situations where the initial message transmission is to an intermediary system. Requirements Supports multi-hop routing. Comments References SHALL be a reference to an actual FHIR resource, and SHALL be resolveable (allowing for access control, temporary unavailability, etc.). Resolution can be either by retrieval from the URL, or, where applicable by resource type, by treating an absolute reference as a canonical URL and looking it up in a local registry/repository. Data Type Reference(UK Core Device) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) rim:unique(./entity[determinerCode="INST" and (classCode=("DEV", "PSN", "ORG"]
reference	Σ I	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.destination.target.reference Short description Literal reference, Relative, internal or absolute URL Definition A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources. Comments Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
type	Σ	0..1	uriBinding	There are no (further) constraints on this element Element Id MessageHeader.destination.target.type Short description Type the reference refers to (e.g. "Patient") Definition The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent. The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources). Comments This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified. Data Type uri Binding Aa resource (or, for logical models, the URI of the logical model). ResourceType (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
identifier	Σ	0..1	Identifier	There are no (further) constraints on this element Element Id MessageHeader.destination.target.identifier Short description Logical reference, when literal reference is not known Definition An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference. Comments When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation\|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any). Data Type Identifier Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CX / EI (occasionally, more often EI maps to a resource id or a URL) rim:II - The Identifier class is a little looser than the v3 type II because it allows URIs as well as registered OIDs or GUIDs. Also maps to Role[classCode=IDENT] servd:Identifier rim:.identifier
use	Σ ?!	0..1	codeBinding	There are no (further) constraints on this element Element Id MessageHeader.destination.target.identifier.use Short description usual \| official \| temp \| secondary \| old (If known) Definition The purpose of this identifier. Requirements Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers. Comments Applications can assume that an identifier is permanent unless it explicitly says that it is temporary. Data Type code Binding Identifies the purpose for this identifier, if known . IdentifierUse (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:N/A rim:Role.code or implied by context
type	Σ	0..1	CodeableConceptBinding	There are no (further) constraints on this element Element Id MessageHeader.destination.target.identifier.type Short description Description of identifier Definition A coded type for the identifier that can be used to determine which identifier to use for a specific purpose. Requirements Allows users to make use of identifiers when the identifier system is not known. Comments This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type. Data Type CodeableConcept Binding A coded type for an identifier that can be used to determine which identifier to use for a specific purpose. Identifier Type Codes (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD v2:CX.5 rim:Role.code or implied by context
system	Σ	0..1	uri	There are no (further) constraints on this element Element Id MessageHeader.destination.target.identifier.system Short description The namespace for the identifier value Definition Establishes the namespace for the value - that is, a URL that describes a set values that are unique. Requirements There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers. Comments Identifier.system is always case sensitive. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General http://www.acme.com/identifiers/patient Mappings rim:n/a v2:CX.4 / EI-2-4 rim:II.root or Role.id.root servd:./IdentifierType
value	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.destination.target.identifier.value Short description The value that is unique Definition The portion of the identifier typically relevant to the user and which is unique within the context of the system. Comments If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General 123456 Mappings rim:n/a v2:CX.1 / EI.1 rim:II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root) servd:./Value
period	Σ I	0..1	Period	There are no (further) constraints on this element Element Id MessageHeader.destination.target.identifier.period Short description Time period when id is/was valid for use Definition Time period during which identifier is/was valid for use. Comments A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). Period is not used for a duration (a measure of elapsed time). See Duration. Data Type Period Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` per-1:If present, start SHALL have a lower value than end `start.hasValue().not() or end.hasValue().not() or (start <= end)` Mappings rim:n/a v2:DR rim:IVL<TS>[lowClosed="true" and highClosed="true"] or URG<TS>[lowClosed="true" and highClosed="true"] v2:CX.7 + CX.8 rim:Role.effectiveTime or implied by context servd:./StartDate and ./EndDate
assigner	Σ I	0..1	Reference(UK Core Organization)	There are no (further) constraints on this element Element Id MessageHeader.destination.target.identifier.assigner Short description Organization that issued id (may be just text) Definition Organization that issued/manages the identifier. Comments The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization. Data Type Reference(UK Core Organization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:CX.4 / (CX.4,CX.9,CX.10) rim:II.assigningAuthorityName but note that this is an improper use by the definition of the field. Also Role.scoper servd:./IdentifierIssuingAuthority
display	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.destination.target.display Short description Text alternative for the resource Definition Plain text narrative that identifies the resource in addition to the resource reference. Comments This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
endpoint	Σ	1..1	url	There are no (further) constraints on this element Element Id MessageHeader.destination.endpoint Short description Actual destination address or id Definition Indicates where the message should be routed to. Requirements Identifies where to route the message. Comments The id may be a non-resolvable URI for systems that do not use standard network-based addresses. Data Type url Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:MSH-25 (or MSH-6) rim:./telecom
receiver	Σ I	1..1	Reference(NHSDigitalPractitionerRole \| NHSDigitalPractitioner \| NHSDigitalOrganization)	Element Id MessageHeader.destination.receiver Short description Intended "real-world" recipient for the data Definition Allows data conveyed by a message to be addressed to a particular person or department when routing to a specific application isn't sufficient. Requirements Allows routing beyond just the application level. Comments References SHALL be a reference to an actual FHIR resource, and SHALL be resolveable (allowing for access control, temporary unavailability, etc.). Resolution can be either by retrieval from the URL, or, where applicable by resource type, by treating an absolute reference as a canonical URL and looking it up in a local registry/repository. Data Type Reference(NHSDigitalPractitionerRole \| NHSDigitalPractitioner \| NHSDigitalOrganization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) w5:FiveWs.subject[x] v2:PRT-5:PRT-4='WAYR' / PRT-8:PRT-4='WAYR' rim:Not directly supported. Could be shared using attentionLine.value with an appropriate keyWordText w5:FiveWs.subject
extension	I	0..*	Extension	Element Id MessageHeader.destination.receiver.extension Short description Additional content defined by implementations Alternate names extensions, user content Definition May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Comments There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone. Data Type Extension Sliced: Unordered, Open, by url(Value) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ext-1:Must have either extensions or value[x], not both `extension.exists() != value.exists()` Mappings rim:n/a rim:N/A
receiverLocalPart	I	0..1	Extension(Reference(NHSDigitalHealthcareService \| NHSDigitalPractitionerRole \| NHSDigitalPractitioner))	Element Id MessageHeader.destination.receiver.extension:receiverLocalPart Short description Optional Extensions Element Alternate names extensions, user content Definition Optional Extension Element - found in all resources. Comments There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone. Data Type Extension(Reference(NHSDigitalHealthcareService \| NHSDigitalPractitionerRole \| NHSDigitalPractitioner)) Extension URL https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-LocalPart Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ext-1:Must have either extensions or value[x], not both `extension.exists() != value.exists()` Mappings rim:n/a rim:N/A
reference	Σ I	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.destination.receiver.reference Short description Literal reference, Relative, internal or absolute URL Definition A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources. Comments Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
type	Σ	0..1	uriBinding	There are no (further) constraints on this element Element Id MessageHeader.destination.receiver.type Short description Type the reference refers to (e.g. "Patient") Definition The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent. The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources). Comments This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified. Data Type uri Binding Aa resource (or, for logical models, the URI of the logical model). ResourceType (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
identifier	Σ	1..1	Identifier	There are no (further) constraints on this element Element Id MessageHeader.destination.receiver.identifier Short description Logical reference, when literal reference is not known Definition An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference. Comments When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation\|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any). Data Type Identifier Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CX / EI (occasionally, more often EI maps to a resource id or a URL) rim:II - The Identifier class is a little looser than the v3 type II because it allows URIs as well as registered OIDs or GUIDs. Also maps to Role[classCode=IDENT] servd:Identifier rim:.identifier
use	Σ ?!	0..1	codeBinding	There are no (further) constraints on this element Element Id MessageHeader.destination.receiver.identifier.use Short description usual \| official \| temp \| secondary \| old (If known) Definition The purpose of this identifier. Requirements Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers. Comments Applications can assume that an identifier is permanent unless it explicitly says that it is temporary. Data Type code Binding Identifies the purpose for this identifier, if known . IdentifierUse (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:N/A rim:Role.code or implied by context
type	Σ	0..1	CodeableConceptBinding	There are no (further) constraints on this element Element Id MessageHeader.destination.receiver.identifier.type Short description Description of identifier Definition A coded type for the identifier that can be used to determine which identifier to use for a specific purpose. Requirements Allows users to make use of identifiers when the identifier system is not known. Comments This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type. Data Type CodeableConcept Binding A coded type for an identifier that can be used to determine which identifier to use for a specific purpose. Identifier Type Codes (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD v2:CX.5 rim:Role.code or implied by context
system	Σ	1..1	uri	There are no (further) constraints on this element Element Id MessageHeader.destination.receiver.identifier.system Short description The namespace for the identifier value Definition Establishes the namespace for the value - that is, a URL that describes a set values that are unique. Requirements There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers. Comments Identifier.system is always case sensitive. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General http://www.acme.com/identifiers/patient Mappings rim:n/a v2:CX.4 / EI-2-4 rim:II.root or Role.id.root servd:./IdentifierType
value	Σ	1..1	string	There are no (further) constraints on this element Element Id MessageHeader.destination.receiver.identifier.value Short description The value that is unique Definition The portion of the identifier typically relevant to the user and which is unique within the context of the system. Comments If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General 123456 Mappings rim:n/a v2:CX.1 / EI.1 rim:II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root) servd:./Value
period	Σ I	0..1	Period	There are no (further) constraints on this element Element Id MessageHeader.destination.receiver.identifier.period Short description Time period when id is/was valid for use Definition Time period during which identifier is/was valid for use. Comments A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). Period is not used for a duration (a measure of elapsed time). See Duration. Data Type Period Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` per-1:If present, start SHALL have a lower value than end `start.hasValue().not() or end.hasValue().not() or (start <= end)` Mappings rim:n/a v2:DR rim:IVL<TS>[lowClosed="true" and highClosed="true"] or URG<TS>[lowClosed="true" and highClosed="true"] v2:CX.7 + CX.8 rim:Role.effectiveTime or implied by context servd:./StartDate and ./EndDate
assigner	Σ I	0..1	Reference(UK Core Organization)	There are no (further) constraints on this element Element Id MessageHeader.destination.receiver.identifier.assigner Short description Organization that issued id (may be just text) Definition Organization that issued/manages the identifier. Comments The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization. Data Type Reference(UK Core Organization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:CX.4 / (CX.4,CX.9,CX.10) rim:II.assigningAuthorityName but note that this is an improper use by the definition of the field. Also Role.scoper servd:./IdentifierIssuingAuthority
display	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.destination.receiver.display Short description Text alternative for the resource Definition Plain text narrative that identifies the resource in addition to the resource reference. Comments This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
sender	S Σ I	0..1	Reference(NHSDigitalPractitionerRole \| NHSDigitalPractitioner \| NHSDigitalOrganization)	Element Id MessageHeader.sender Short description Real world sender of the message Definition The current requirement in NHS Digital API's is to rely on the Access Tokens and Audit (JWT) for sender details. For use outside of NHS Digital it is recommended this is populated with either the Organisation ODS code or the Practitioner's professional code. `"sender": { "identifier": { "system": "https://fhir.nhs.uk/Id/ods-organization-code", "value": "VNE51" } }` Requirements Allows routing beyond just the application level. Comments Use case is for where a (trusted) sending system is responsible for multiple organizations, and therefore cannot differentiate based on source endpoint / authentication alone. Data Type Reference(NHSDigitalPractitionerRole \| NHSDigitalPractitioner \| NHSDigitalOrganization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) w5:FiveWs.subject[x] v2:PRT-5:PRT-4='WAYR' / PRT-8:PRT-4='WAYR' rim:Not directly supported. Could be shared using attentionLine.value with an appropriate keyWordText w5:FiveWs.subject
extension	I	0..*	Extension	Element Id MessageHeader.sender.extension Short description Additional content defined by implementations Alternate names extensions, user content Definition May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Comments There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone. Data Type Extension Sliced: Unordered, Open, by url(Value) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ext-1:Must have either extensions or value[x], not both `extension.exists() != value.exists()` Mappings rim:n/a rim:N/A
senderLocalPart	I	0..1	Extension(Reference(NHSDigitalHealthcareService \| NHSDigitalPractitionerRole \| NHSDigitalPractitioner))	Element Id MessageHeader.sender.extension:senderLocalPart Short description Optional Extensions Element Alternate names extensions, user content Definition Optional Extension Element - found in all resources. Comments There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone. Data Type Extension(Reference(NHSDigitalHealthcareService \| NHSDigitalPractitionerRole \| NHSDigitalPractitioner)) Extension URL https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-LocalPart Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ext-1:Must have either extensions or value[x], not both `extension.exists() != value.exists()` Mappings rim:n/a rim:N/A
reference	Σ I	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.sender.reference Short description Literal reference, Relative, internal or absolute URL Definition A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources. Comments Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
type	Σ	0..1	uriBinding	There are no (further) constraints on this element Element Id MessageHeader.sender.type Short description Type the reference refers to (e.g. "Patient") Definition The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent. The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources). Comments This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified. Data Type uri Binding Aa resource (or, for logical models, the URI of the logical model). ResourceType (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
identifier	S Σ	1..1	Identifier	There are no (further) constraints on this element Element Id MessageHeader.sender.identifier Short description Logical reference, when literal reference is not known Definition An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference. Comments When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation\|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any). Data Type Identifier Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CX / EI (occasionally, more often EI maps to a resource id or a URL) rim:II - The Identifier class is a little looser than the v3 type II because it allows URIs as well as registered OIDs or GUIDs. Also maps to Role[classCode=IDENT] servd:Identifier rim:.identifier
use	Σ ?!	0..1	codeBinding	There are no (further) constraints on this element Element Id MessageHeader.sender.identifier.use Short description usual \| official \| temp \| secondary \| old (If known) Definition The purpose of this identifier. Requirements Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers. Comments Applications can assume that an identifier is permanent unless it explicitly says that it is temporary. Data Type code Binding Identifies the purpose for this identifier, if known . IdentifierUse (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:N/A rim:Role.code or implied by context
type	Σ	0..1	CodeableConceptBinding	There are no (further) constraints on this element Element Id MessageHeader.sender.identifier.type Short description Description of identifier Definition A coded type for the identifier that can be used to determine which identifier to use for a specific purpose. Requirements Allows users to make use of identifiers when the identifier system is not known. Comments This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type. Data Type CodeableConcept Binding A coded type for an identifier that can be used to determine which identifier to use for a specific purpose. Identifier Type Codes (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD v2:CX.5 rim:Role.code or implied by context
system	Σ	1..1	uri	There are no (further) constraints on this element Element Id MessageHeader.sender.identifier.system Short description The namespace for the identifier value Definition Establishes the namespace for the value - that is, a URL that describes a set values that are unique. Requirements There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers. Comments Identifier.system is always case sensitive. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General http://www.acme.com/identifiers/patient Mappings rim:n/a v2:CX.4 / EI-2-4 rim:II.root or Role.id.root servd:./IdentifierType
value	Σ	1..1	string	There are no (further) constraints on this element Element Id MessageHeader.sender.identifier.value Short description The value that is unique Definition The portion of the identifier typically relevant to the user and which is unique within the context of the system. Comments If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General 123456 Mappings rim:n/a v2:CX.1 / EI.1 rim:II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root) servd:./Value
period	Σ I	0..1	Period	There are no (further) constraints on this element Element Id MessageHeader.sender.identifier.period Short description Time period when id is/was valid for use Definition Time period during which identifier is/was valid for use. Comments A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). Period is not used for a duration (a measure of elapsed time). See Duration. Data Type Period Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` per-1:If present, start SHALL have a lower value than end `start.hasValue().not() or end.hasValue().not() or (start <= end)` Mappings rim:n/a v2:DR rim:IVL<TS>[lowClosed="true" and highClosed="true"] or URG<TS>[lowClosed="true" and highClosed="true"] v2:CX.7 + CX.8 rim:Role.effectiveTime or implied by context servd:./StartDate and ./EndDate
assigner	Σ I	0..1	Reference(UK Core Organization)	There are no (further) constraints on this element Element Id MessageHeader.sender.identifier.assigner Short description Organization that issued id (may be just text) Definition Organization that issued/manages the identifier. Comments The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization. Data Type Reference(UK Core Organization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:CX.4 / (CX.4,CX.9,CX.10) rim:II.assigningAuthorityName but note that this is an improper use by the definition of the field. Also Role.scoper servd:./IdentifierIssuingAuthority
display	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.sender.display Short description Text alternative for the resource Definition Plain text narrative that identifies the resource in addition to the resource reference. Comments This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
enterer	Σ I	0..1	Reference(NHSDigitalPractitionerRole \| NHSDigitalPractitioner)	Element Id MessageHeader.enterer Short description The source of the data entry Definition The person or device that performed the data entry leading to this message. When there is more than one candidate, pick the most proximal to the message. Can provide other enterers in extensions. Requirements Need to know for audit/traceback requirements and possibly for authorization. Comments Usually only for the request but can be used in a response. Data Type Reference(NHSDigitalPractitionerRole \| NHSDigitalPractitioner) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) w5:FiveWs.author v2:EVN-5 / ORC-10 / PRT-5:PRT-4='EP' / ROL where ROL.3 is EP or ORC.10 rim:unique(./controlAct[classCode="CACT" and classCode="EVN" and isNormalAct()]/participation[typeCode="ENT" and isNormalParticipation]/role[classCode="ASSIGNED" and isNormalRole()]/player[isNormalEntity() and classCode=("DEV", "PSN") and determinerCode="INST"])
reference	Σ I	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.enterer.reference Short description Literal reference, Relative, internal or absolute URL Definition A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources. Comments Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
type	Σ	0..1	uriBinding	There are no (further) constraints on this element Element Id MessageHeader.enterer.type Short description Type the reference refers to (e.g. "Patient") Definition The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent. The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources). Comments This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified. Data Type uri Binding Aa resource (or, for logical models, the URI of the logical model). ResourceType (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
identifier	Σ	0..1	Identifier	There are no (further) constraints on this element Element Id MessageHeader.enterer.identifier Short description Logical reference, when literal reference is not known Definition An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference. Comments When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation\|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any). Data Type Identifier Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CX / EI (occasionally, more often EI maps to a resource id or a URL) rim:II - The Identifier class is a little looser than the v3 type II because it allows URIs as well as registered OIDs or GUIDs. Also maps to Role[classCode=IDENT] servd:Identifier rim:.identifier
use	Σ ?!	0..1	codeBinding	There are no (further) constraints on this element Element Id MessageHeader.enterer.identifier.use Short description usual \| official \| temp \| secondary \| old (If known) Definition The purpose of this identifier. Requirements Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers. Comments Applications can assume that an identifier is permanent unless it explicitly says that it is temporary. Data Type code Binding Identifies the purpose for this identifier, if known . IdentifierUse (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:N/A rim:Role.code or implied by context
type	Σ	0..1	CodeableConceptBinding	There are no (further) constraints on this element Element Id MessageHeader.enterer.identifier.type Short description Description of identifier Definition A coded type for the identifier that can be used to determine which identifier to use for a specific purpose. Requirements Allows users to make use of identifiers when the identifier system is not known. Comments This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type. Data Type CodeableConcept Binding A coded type for an identifier that can be used to determine which identifier to use for a specific purpose. Identifier Type Codes (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD v2:CX.5 rim:Role.code or implied by context
system	Σ	0..1	uri	There are no (further) constraints on this element Element Id MessageHeader.enterer.identifier.system Short description The namespace for the identifier value Definition Establishes the namespace for the value - that is, a URL that describes a set values that are unique. Requirements There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers. Comments Identifier.system is always case sensitive. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General http://www.acme.com/identifiers/patient Mappings rim:n/a v2:CX.4 / EI-2-4 rim:II.root or Role.id.root servd:./IdentifierType
value	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.enterer.identifier.value Short description The value that is unique Definition The portion of the identifier typically relevant to the user and which is unique within the context of the system. Comments If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General 123456 Mappings rim:n/a v2:CX.1 / EI.1 rim:II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root) servd:./Value
period	Σ I	0..1	Period	There are no (further) constraints on this element Element Id MessageHeader.enterer.identifier.period Short description Time period when id is/was valid for use Definition Time period during which identifier is/was valid for use. Comments A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). Period is not used for a duration (a measure of elapsed time). See Duration. Data Type Period Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` per-1:If present, start SHALL have a lower value than end `start.hasValue().not() or end.hasValue().not() or (start <= end)` Mappings rim:n/a v2:DR rim:IVL<TS>[lowClosed="true" and highClosed="true"] or URG<TS>[lowClosed="true" and highClosed="true"] v2:CX.7 + CX.8 rim:Role.effectiveTime or implied by context servd:./StartDate and ./EndDate
assigner	Σ I	0..1	Reference(UK Core Organization)	There are no (further) constraints on this element Element Id MessageHeader.enterer.identifier.assigner Short description Organization that issued id (may be just text) Definition Organization that issued/manages the identifier. Comments The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization. Data Type Reference(UK Core Organization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:CX.4 / (CX.4,CX.9,CX.10) rim:II.assigningAuthorityName but note that this is an improper use by the definition of the field. Also Role.scoper servd:./IdentifierIssuingAuthority
display	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.enterer.display Short description Text alternative for the resource Definition Plain text narrative that identifies the resource in addition to the resource reference. Comments This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
author	Σ I	0..1	Reference(NHSDigitalPractitionerRole \| NHSDigitalPractitioner)	Element Id MessageHeader.author Short description The source of the decision Definition If present, this SHOULD be an identifier reference to a `Practitioner` or `PractitionerRole`. Internal references to resources should NOT be used. `"author": { "type": "PractitionerRole", "identifier": { "system": "https://fhir.nhs.uk/Id/sds-role-profile-id", "value": "100102238986" }, "display": "DR ALI" },` Requirements Need to know for audit/traceback requirements and possibly for authorization. Comments Usually only for the request but can be used in a response. Data Type Reference(NHSDigitalPractitionerRole \| NHSDigitalPractitioner) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) w5:FiveWs.author v2:ORC-19 / PRT-5:PRT-4='AUT' / ROL where ROL.3 is IP or ORC.12 rim:unique(./controlAct[classCode="CACT" and classCode="EVN" and isNormalAct()]/participation[isHighest(priorityCode) and typeCode="AUT" and isNormalParticipation]/role[classCode="ASSIGNED" and isNormalRole()]/player[isNormalEntity() and classCode=("DEV", "PSN") and determinerCode="INST"])
reference	Σ I	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.author.reference Short description Literal reference, Relative, internal or absolute URL Definition A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources. Comments Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
type	Σ	0..1	uriBinding	There are no (further) constraints on this element Element Id MessageHeader.author.type Short description Type the reference refers to (e.g. "Patient") Definition The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent. The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources). Comments This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified. Data Type uri Binding Aa resource (or, for logical models, the URI of the logical model). ResourceType (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
identifier	Σ	1..1	Identifier	There are no (further) constraints on this element Element Id MessageHeader.author.identifier Short description Logical reference, when literal reference is not known Definition An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference. Comments When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation\|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any). Data Type Identifier Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CX / EI (occasionally, more often EI maps to a resource id or a URL) rim:II - The Identifier class is a little looser than the v3 type II because it allows URIs as well as registered OIDs or GUIDs. Also maps to Role[classCode=IDENT] servd:Identifier rim:.identifier
use	Σ ?!	0..1	codeBinding	There are no (further) constraints on this element Element Id MessageHeader.author.identifier.use Short description usual \| official \| temp \| secondary \| old (If known) Definition The purpose of this identifier. Requirements Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers. Comments Applications can assume that an identifier is permanent unless it explicitly says that it is temporary. Data Type code Binding Identifies the purpose for this identifier, if known . IdentifierUse (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:N/A rim:Role.code or implied by context
type	Σ	0..1	CodeableConceptBinding	There are no (further) constraints on this element Element Id MessageHeader.author.identifier.type Short description Description of identifier Definition A coded type for the identifier that can be used to determine which identifier to use for a specific purpose. Requirements Allows users to make use of identifiers when the identifier system is not known. Comments This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type. Data Type CodeableConcept Binding A coded type for an identifier that can be used to determine which identifier to use for a specific purpose. Identifier Type Codes (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD v2:CX.5 rim:Role.code or implied by context
system	Σ	1..1	uri	There are no (further) constraints on this element Element Id MessageHeader.author.identifier.system Short description The namespace for the identifier value Definition Establishes the namespace for the value - that is, a URL that describes a set values that are unique. Requirements There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers. Comments Identifier.system is always case sensitive. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General http://www.acme.com/identifiers/patient Mappings rim:n/a v2:CX.4 / EI-2-4 rim:II.root or Role.id.root servd:./IdentifierType
value	Σ	1..1	string	There are no (further) constraints on this element Element Id MessageHeader.author.identifier.value Short description The value that is unique Definition The portion of the identifier typically relevant to the user and which is unique within the context of the system. Comments If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General 123456 Mappings rim:n/a v2:CX.1 / EI.1 rim:II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root) servd:./Value
period	Σ I	0..1	Period	There are no (further) constraints on this element Element Id MessageHeader.author.identifier.period Short description Time period when id is/was valid for use Definition Time period during which identifier is/was valid for use. Comments A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). Period is not used for a duration (a measure of elapsed time). See Duration. Data Type Period Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` per-1:If present, start SHALL have a lower value than end `start.hasValue().not() or end.hasValue().not() or (start <= end)` Mappings rim:n/a v2:DR rim:IVL<TS>[lowClosed="true" and highClosed="true"] or URG<TS>[lowClosed="true" and highClosed="true"] v2:CX.7 + CX.8 rim:Role.effectiveTime or implied by context servd:./StartDate and ./EndDate
assigner	Σ I	0..1	Reference(UK Core Organization)	There are no (further) constraints on this element Element Id MessageHeader.author.identifier.assigner Short description Organization that issued id (may be just text) Definition Organization that issued/manages the identifier. Comments The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization. Data Type Reference(UK Core Organization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:CX.4 / (CX.4,CX.9,CX.10) rim:II.assigningAuthorityName but note that this is an improper use by the definition of the field. Also Role.scoper servd:./IdentifierIssuingAuthority
display	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.author.display Short description Text alternative for the resource Definition Plain text narrative that identifies the resource in addition to the resource reference. Comments This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
source	S Σ	1..1	BackboneElement	Element Id MessageHeader.source Short description Message source application Definition `source.endpoint` is required and MUST indicate the address where replies are to be sent. For responses to be received via http this will be the address of the `$process-message` endpoint. E.g. `https://fhir.hospitaltrust.nhs.uk/$process-message` For MESH this will follow ITK2.2 MESH Transport Requirements for ITK Routing. E.g. the MESH Endpoint for Organisation B80310 `"source": { "endpoint": "urn:nhs-uk:addressing:mesh:Y90638OT001" }` Requirements Allows replies, supports audit. Data Type BackboneElement Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a w5:FiveWs.actor rim:unique(./communicationFunction[typeCode="SND"])
name	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.source.name Short description Name of system Definition Human-readable name for the source system. Requirements May be used to support audit. Comments Note that FHIR strings SHALL NOT exceed 1MB in size Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:MSH-3 rim:unique(./entity[determinerCode="INST" and classCode="DEV"]/name[type='ST' and isNormalDatatype()])
software	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.source.software Short description Name of software running the system Definition May include configuration or other information useful in debugging. Requirements Supports audit and possibly interface engine behavior. Comments Note that FHIR strings SHALL NOT exceed 1MB in size Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:SFT-3 ( +SFT-1) rim:unique(./entity[determinerCode="INST" and classCode="DEV"]/softwareName[isNormalDatatype()])
version	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.source.version Short description Version of software running Definition Can convey versions of multiple systems in situations where a message passes through multiple hands. Requirements Supports audit and possibly interface engine behavior. Comments Note that FHIR strings SHALL NOT exceed 1MB in size Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:SFT-2 rim:(Not supported)
contact	Σ I	0..1	ContactPoint	There are no (further) constraints on this element Element Id MessageHeader.source.contact Short description Human contact for problems Definition An e-mail, phone, website or other contact point to use to resolve issues with message communications. Requirements Allows escalation of technical issues. Data Type ContactPoint Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` cpt-2:A system is required if a value is provided. `value.empty() or system.exists()` Mappings rim:n/a v2:XTN rim:TEL servd:ContactPoint v2:(MSH-22?) rim:unique(./entity[determinerCode="INST" and classCode="DEV"]/scopesRole[normalRole() and classCode="CON" and layer[classCode="PSN"]/telecom[isNormalDatatype()])
endpoint	Σ	1..1	url	There are no (further) constraints on this element Element Id MessageHeader.source.endpoint Short description Actual message source address or id Definition Identifies the routing target to send acknowledgements to. Requirements Identifies where to send responses, may influence security permissions. Comments The id may be a non-resolvable URI for systems that do not use standard network-based addresses. Data Type url Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:MSH-24 rim:./telecom[isNormalDatatype()]
responsible	Σ I	0..1	Reference(NHSDigitalPractitioner \| NHSDigitalOrganization)	Element Id MessageHeader.responsible Short description Final responsibility for event Definition The person or organization that accepts overall responsibility for the contents of the message. The implication is that the message event happened under the policies of the responsible party. Requirements Need to know for audit/traceback requirements and possibly for authorization. Comments Usually only for the request but can be used in a response. Data Type Reference(NHSDigitalPractitioner \| NHSDigitalOrganization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) w5:FiveWs.witness v2:ORC-12 / PRT-5:PRT-4='OP' / PRT-8:PRT-4='OP' / ROL where ROL.3 is RO or ORC.11 rim:unique(./controlAct[classCode="CACT" and classCode="EVN" and isNormalAct()]/participation[isHighest(priorityCode) and typeCode="RESP" and isNormalParticipation]/role[classCode="ASSIGNED" and isNormalRole()]/player[isNormalEntity() and classCode="PSN" and determinerCode="INST"] or ./controlAct[classCode="CACT" and classCode="EVN" and isNormalAct()]/participation[isHighest(priorityCode) and typeCode="RESP" and isNormalParticipation]/role[classCode="ASSIGNED" and isNormalRole()]/scoper[isNormalEntity() and classCode="ORG" and determinerCode="INST"])
reference	Σ I	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.responsible.reference Short description Literal reference, Relative, internal or absolute URL Definition A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources. Comments Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
type	Σ	0..1	uriBinding	There are no (further) constraints on this element Element Id MessageHeader.responsible.type Short description Type the reference refers to (e.g. "Patient") Definition The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent. The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources). Comments This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified. Data Type uri Binding Aa resource (or, for logical models, the URI of the logical model). ResourceType (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
identifier	Σ	1..1	Identifier	There are no (further) constraints on this element Element Id MessageHeader.responsible.identifier Short description Logical reference, when literal reference is not known Definition An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference. Comments When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation\|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any). Data Type Identifier Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CX / EI (occasionally, more often EI maps to a resource id or a URL) rim:II - The Identifier class is a little looser than the v3 type II because it allows URIs as well as registered OIDs or GUIDs. Also maps to Role[classCode=IDENT] servd:Identifier rim:.identifier
use	Σ ?!	0..1	codeBinding	There are no (further) constraints on this element Element Id MessageHeader.responsible.identifier.use Short description usual \| official \| temp \| secondary \| old (If known) Definition The purpose of this identifier. Requirements Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers. Comments Applications can assume that an identifier is permanent unless it explicitly says that it is temporary. Data Type code Binding Identifies the purpose for this identifier, if known . IdentifierUse (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:N/A rim:Role.code or implied by context
type	Σ	0..1	CodeableConceptBinding	There are no (further) constraints on this element Element Id MessageHeader.responsible.identifier.type Short description Description of identifier Definition A coded type for the identifier that can be used to determine which identifier to use for a specific purpose. Requirements Allows users to make use of identifiers when the identifier system is not known. Comments This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type. Data Type CodeableConcept Binding A coded type for an identifier that can be used to determine which identifier to use for a specific purpose. Identifier Type Codes (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD v2:CX.5 rim:Role.code or implied by context
system	Σ	1..1	uri	There are no (further) constraints on this element Element Id MessageHeader.responsible.identifier.system Short description The namespace for the identifier value Definition Establishes the namespace for the value - that is, a URL that describes a set values that are unique. Requirements There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers. Comments Identifier.system is always case sensitive. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General http://www.acme.com/identifiers/patient Mappings rim:n/a v2:CX.4 / EI-2-4 rim:II.root or Role.id.root servd:./IdentifierType
value	Σ	1..1	string	There are no (further) constraints on this element Element Id MessageHeader.responsible.identifier.value Short description The value that is unique Definition The portion of the identifier typically relevant to the user and which is unique within the context of the system. Comments If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General 123456 Mappings rim:n/a v2:CX.1 / EI.1 rim:II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root) servd:./Value
period	Σ I	0..1	Period	There are no (further) constraints on this element Element Id MessageHeader.responsible.identifier.period Short description Time period when id is/was valid for use Definition Time period during which identifier is/was valid for use. Comments A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). Period is not used for a duration (a measure of elapsed time). See Duration. Data Type Period Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` per-1:If present, start SHALL have a lower value than end `start.hasValue().not() or end.hasValue().not() or (start <= end)` Mappings rim:n/a v2:DR rim:IVL<TS>[lowClosed="true" and highClosed="true"] or URG<TS>[lowClosed="true" and highClosed="true"] v2:CX.7 + CX.8 rim:Role.effectiveTime or implied by context servd:./StartDate and ./EndDate
assigner	Σ I	0..1	Reference(UK Core Organization)	There are no (further) constraints on this element Element Id MessageHeader.responsible.identifier.assigner Short description Organization that issued id (may be just text) Definition Organization that issued/manages the identifier. Comments The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization. Data Type Reference(UK Core Organization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:CX.4 / (CX.4,CX.9,CX.10) rim:II.assigningAuthorityName but note that this is an improper use by the definition of the field. Also Role.scoper servd:./IdentifierIssuingAuthority
display	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.responsible.display Short description Text alternative for the resource Definition Plain text narrative that identifies the resource in addition to the resource reference. Comments This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
reason	Σ	0..1	CodeableConceptBinding	Element Id MessageHeader.reason Short description Cause of event Definition `reason` can be used to subdivide `eventCoding`. In the example below, `cancel` is used to indicate the specific reason for the event `prescription-order-update`. The physical cancellation would be the `status=cancelled` in the `MedicationRequest` reason, the reason is a hint. `"reason": { "coding": [ { "system": "https://fhir.nhs.uk/CodeSystem/message-reason-prescription", "code": "cancel", "display": "Cancel" } ] }` Requirements Need to be able to track why resources are being changed and report in the audit log/history of the resource. May affect authorization. Comments Not all terminology uses fit this general pattern. In some cases, models should not use CodeableConcept and use Coding directly and provide their own structure for managing text, codings, translations and the relationship between elements and pre- and post-coordination. Data Type CodeableConcept Binding Reason for event occurrence. MessageReasonCodes (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD w5:FiveWs.why[x] v2:EVN.4 / ORC.16 / OBR-31-reason for study / BPO-13-BP indication for use / RXO-20-indication / RXE-27-give indication / RXD-21-indication / RXG-22-indication / RXA-19-indication rim:unique(./controlAct[classCode="CACT" and classCode="EVN" and isNormalAct()]/reasonCode[isNormalDatatype()])
coding	Σ	0..*	Coding	There are no (further) constraints on this element Element Id MessageHeader.reason.coding Short description Code defined by a terminology system Definition A reference to a code defined by a terminology system. Requirements Allows for alternative encodings within a code system, and translations to other code systems. Comments Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true. Data Type Coding Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE subset one of the sets of component 1-3 or 4-6 rim:CV orim:fhir:Coding rdfs:subClassOf dt:CDCoding v2:CE.1-8, CE.10-22 rim:union(., ./translation) orim:fhir:CodeableConcept.coding rdfs:subPropertyOf dt:CD.coding
system	Σ	1..1	uri	There are no (further) constraints on this element Element Id MessageHeader.reason.coding.system Short description Identity of the terminology system Definition The identification of the code system that defines the meaning of the symbol in the code. Requirements Need to be unambiguous about the source of the definition of the symbol. Comments The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should reference to some definition that establishes the system clearly and unambiguously. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE.3 rim:./codeSystem orim:*fhir:Coding.system rdfs:subPropertyOf dt:CDCoding.codeSystem
version	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.reason.coding.version Short description Version of the system - if relevant Definition The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured, and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged. Comments Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE.7 rim:./codeSystemVersion orim:*fhir:Coding.version rdfs:subPropertyOf dt:CDCoding.codeSystemVersion
code	Σ	1..1	code	There are no (further) constraints on this element Element Id MessageHeader.reason.coding.code Short description Symbol in syntax defined by the system Definition A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination). Requirements Need to refer to a particular code in the system. Comments Note that FHIR strings SHALL NOT exceed 1MB in size Data Type code Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE.1 rim:./code orim:*fhir:Coding.code rdfs:subPropertyOf dt:CDCoding.code
display	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.reason.coding.display Short description Representation defined by the system Definition A representation of the meaning of the code in the system, following the rules of the system. Requirements Need to be able to carry a human-readable meaning of the code for readers that do not know the system. Comments Note that FHIR strings SHALL NOT exceed 1MB in size Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE.2 - but note this is not well followed rim:CV.displayName orim:*fhir:Coding.display rdfs:subPropertyOf dt:CDCoding.displayName
userSelected	Σ	0..1	boolean	There are no (further) constraints on this element Element Id MessageHeader.reason.coding.userSelected Short description If this coding was chosen directly by the user Definition Indicates that this coding was chosen by a user directly - e.g. off a pick list of available items (codes or displays). Requirements This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing. Comments Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely. Data Type boolean Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:Sometimes implied by being first rim:CD.codingRationale orim:fhir:Coding.userSelected fhir:mapsTo dt:CDCoding.codingRationale. fhir:Coding.userSelected fhir:hasMap fhir:Coding.userSelected.map. fhir:Coding.userSelected.map a fhir:Map; fhir:target dt:CDCoding.codingRationale. fhir:Coding.userSelected\#true a [ fhir:source "true"; fhir:target dt:CDCoding.codingRationale\#O ]
text	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.reason.text Short description Plain text representation of the concept Definition A human language representation of the concept as seen/selected/uttered by the user who entered the data and/or which represents the intended meaning of the user. Requirements The codes from the terminologies do not always capture the correct meaning with all the nuances of the human using them, or sometimes there is no appropriate code at all. In these cases, the text is used to capture the full meaning of the source. Comments Very often the text is the same as a displayName of one of the codings. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE.9. But note many systems use CE.2 for this rim:./originalText[mediaType/code="text/plain"]/data orim:fhir:CodeableConcept.text rdfs:subPropertyOf dt:CD.originalText
response	Σ	0..1	BackboneElement	Element Id MessageHeader.response Short description If this is a reply to prior message Definition If the message is a response to a previous message, the `response.identifier` MUST match the previous request messages `Bundle.identifier` Correlation-ID. `"response": { "identifier": "ad945a29-85f8-439a-b590-6789719adc16", "code": "ok" }` Data Type BackboneElement Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:MSA rim:./conveyedAcknowledgement
identifier	Σ	1..1	id	There are no (further) constraints on this element Element Id MessageHeader.response.identifier Short description Id of original message Definition The MessageHeader.id of the message to which this message is a response. Requirements Allows receiver to know what message is being responded to. Comments RFC 4122 Data Type id Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:MSA-2 rim:./acknowledges.id[isNormalDatatype()]
code	Σ	1..1	codeBinding	There are no (further) constraints on this element Element Id MessageHeader.response.code Short description ok \| transient-error \| fatal-error Definition Code that identifies the type of response to the message - whether it was successful or not, and whether it should be resent or not. Requirements Allows the sender of the acknowledge message to know if the request was successful or if action is needed. Comments This is a generic response to the request message. Specific data for the response will be found in MessageHeader.focus. Data Type code Binding The kind of response to a message. ResponseType (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:MSA-1 rim:./typeCode[isNormalDatatype()]
details	Σ I	0..1	Reference(UK Core OperationOutcome)	There are no (further) constraints on this element Element Id MessageHeader.response.details Short description Specific list of hints/warnings/errors Definition Full details of any issues found in the message. Requirements Allows the sender of the message to determine what the specific issues are. Comments This SHALL be contained in the bundle. If any of the issues are errors, the response code SHALL be an error. Data Type Reference(UK Core OperationOutcome) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:ERR rim:AcknowledgementDetail or Observation[classCode="ALRT" and moodCode="EVN"]
reference	Σ I	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.response.details.reference Short description Literal reference, Relative, internal or absolute URL Definition A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources. Comments Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
type	Σ	0..1	uriBinding	There are no (further) constraints on this element Element Id MessageHeader.response.details.type Short description Type the reference refers to (e.g. "Patient") Definition The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent. The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources). Comments This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified. Data Type uri Binding Aa resource (or, for logical models, the URI of the logical model). ResourceType (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
identifier	Σ	0..1	Identifier	There are no (further) constraints on this element Element Id MessageHeader.response.details.identifier Short description Logical reference, when literal reference is not known Definition An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference. Comments When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation\|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any). Data Type Identifier Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CX / EI (occasionally, more often EI maps to a resource id or a URL) rim:II - The Identifier class is a little looser than the v3 type II because it allows URIs as well as registered OIDs or GUIDs. Also maps to Role[classCode=IDENT] servd:Identifier rim:.identifier
use	Σ ?!	0..1	codeBinding	There are no (further) constraints on this element Element Id MessageHeader.response.details.identifier.use Short description usual \| official \| temp \| secondary \| old (If known) Definition The purpose of this identifier. Requirements Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers. Comments Applications can assume that an identifier is permanent unless it explicitly says that it is temporary. Data Type code Binding Identifies the purpose for this identifier, if known . IdentifierUse (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:N/A rim:Role.code or implied by context
type	Σ	0..1	CodeableConceptBinding	There are no (further) constraints on this element Element Id MessageHeader.response.details.identifier.type Short description Description of identifier Definition A coded type for the identifier that can be used to determine which identifier to use for a specific purpose. Requirements Allows users to make use of identifiers when the identifier system is not known. Comments This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type. Data Type CodeableConcept Binding A coded type for an identifier that can be used to determine which identifier to use for a specific purpose. Identifier Type Codes (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD v2:CX.5 rim:Role.code or implied by context
system	Σ	0..1	uri	There are no (further) constraints on this element Element Id MessageHeader.response.details.identifier.system Short description The namespace for the identifier value Definition Establishes the namespace for the value - that is, a URL that describes a set values that are unique. Requirements There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers. Comments Identifier.system is always case sensitive. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General http://www.acme.com/identifiers/patient Mappings rim:n/a v2:CX.4 / EI-2-4 rim:II.root or Role.id.root servd:./IdentifierType
value	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.response.details.identifier.value Short description The value that is unique Definition The portion of the identifier typically relevant to the user and which is unique within the context of the system. Comments If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General 123456 Mappings rim:n/a v2:CX.1 / EI.1 rim:II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root) servd:./Value
period	Σ I	0..1	Period	There are no (further) constraints on this element Element Id MessageHeader.response.details.identifier.period Short description Time period when id is/was valid for use Definition Time period during which identifier is/was valid for use. Comments A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). Period is not used for a duration (a measure of elapsed time). See Duration. Data Type Period Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` per-1:If present, start SHALL have a lower value than end `start.hasValue().not() or end.hasValue().not() or (start <= end)` Mappings rim:n/a v2:DR rim:IVL<TS>[lowClosed="true" and highClosed="true"] or URG<TS>[lowClosed="true" and highClosed="true"] v2:CX.7 + CX.8 rim:Role.effectiveTime or implied by context servd:./StartDate and ./EndDate
assigner	Σ I	0..1	Reference(UK Core Organization)	There are no (further) constraints on this element Element Id MessageHeader.response.details.identifier.assigner Short description Organization that issued id (may be just text) Definition Organization that issued/manages the identifier. Comments The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization. Data Type Reference(UK Core Organization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:CX.4 / (CX.4,CX.9,CX.10) rim:II.assigningAuthorityName but note that this is an improper use by the definition of the field. Also Role.scoper servd:./IdentifierIssuingAuthority
display	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.response.details.display Short description Text alternative for the resource Definition Plain text narrative that identifies the resource in addition to the resource reference. Comments This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
focus	Σ I	1..*	Reference(Resource)	Element Id MessageHeader.focus Short description The actual content of the message Definition The focus element of the MessageHeader specifies the content of the message. The MessageHeader is followed by other resources depending on the type of request. For example, a request to book an appointment may contain the Patient to book the appointment for, the Practitioner to book the appointment with and the actual Appointment that is requested. The focus section SHOULD match the focus section of the corresponding `MessageDefinition` MessageDefinition.focus extract `"focus": [ { "code": "MedicationRequest", "profile": "https://fhir.nhs.uk/StructureDefinition/NHSDigital-MedicationRequest", "min": 1, "max": "4" }, { "code": "Patient", "profile": "https://fhir.nhs.uk/StructureDefinition/NHSDigital-Patient", "min": 1, "max": "1" }, { "code": "CommunicationRequest", "profile": "https://fhir.nhs.uk/StructureDefinition/DM-CommunicationRequest", "min": 0, "max": "" } ]` Corresponding MessageHeader.focus* (Note: type is not required and is included for illustration purposes) `"focus": [ { "type": "Patient", "reference": "urn:uuid:78d3c2eb-009e-4ec8-a358-b042954aa9b2" }, { "type": "MedicationRequest", "reference": "urn:uuid:a54219b8-f741-4c47-b662-e4f8dfa49ab6" }, { "type": "CommunicationRequest", "reference": "urn:uuid:28828C55-8FA7-42D7-916F-FCF076E0C10E" } ]` Requirements Every message event is about actual data, a single resource, that is identified in the definition of the event, and perhaps some or all linked resources. Comments The data is defined where the transaction type is defined. The transaction data is always included in the bundle that is the full message. Only the root resource is specified. The resources it references should be contained in the bundle but are not also listed here. Multiple repetitions are allowed to cater for merges and other situations with multiple focal targets. Data Type Reference(Resource) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) rim:unique(./controlAct[classCode="CACT" and classCode="EVN" and isNormalAct()]/participation[typeCode="SUBJ" and isNormalParticipation]/role or ./controlAct[classCode="CACT" and classCode="EVN" and isNormalAct()]/outboundRelationship[typeCode="SBJ" and isNormalActRelatoinship]/target)
reference	Σ I	1..1	string	There are no (further) constraints on this element Element Id MessageHeader.focus.reference Short description Literal reference, Relative, internal or absolute URL Definition A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources. Comments Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
type	Σ	0..1	uriBinding	There are no (further) constraints on this element Element Id MessageHeader.focus.type Short description Type the reference refers to (e.g. "Patient") Definition The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent. The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources). Comments This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified. Data Type uri Binding Aa resource (or, for logical models, the URI of the logical model). ResourceType (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
identifier	Σ	0..1	Identifier	There are no (further) constraints on this element Element Id MessageHeader.focus.identifier Short description Logical reference, when literal reference is not known Definition An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference. Comments When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation\|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any). Data Type Identifier Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CX / EI (occasionally, more often EI maps to a resource id or a URL) rim:II - The Identifier class is a little looser than the v3 type II because it allows URIs as well as registered OIDs or GUIDs. Also maps to Role[classCode=IDENT] servd:Identifier rim:.identifier
use	Σ ?!	0..1	codeBinding	There are no (further) constraints on this element Element Id MessageHeader.focus.identifier.use Short description usual \| official \| temp \| secondary \| old (If known) Definition The purpose of this identifier. Requirements Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers. Comments Applications can assume that an identifier is permanent unless it explicitly says that it is temporary. Data Type code Binding Identifies the purpose for this identifier, if known . IdentifierUse (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:N/A rim:Role.code or implied by context
type	Σ	0..1	CodeableConceptBinding	There are no (further) constraints on this element Element Id MessageHeader.focus.identifier.type Short description Description of identifier Definition A coded type for the identifier that can be used to determine which identifier to use for a specific purpose. Requirements Allows users to make use of identifiers when the identifier system is not known. Comments This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type. Data Type CodeableConcept Binding A coded type for an identifier that can be used to determine which identifier to use for a specific purpose. Identifier Type Codes (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD v2:CX.5 rim:Role.code or implied by context
system	Σ	0..1	uri	There are no (further) constraints on this element Element Id MessageHeader.focus.identifier.system Short description The namespace for the identifier value Definition Establishes the namespace for the value - that is, a URL that describes a set values that are unique. Requirements There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers. Comments Identifier.system is always case sensitive. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General http://www.acme.com/identifiers/patient Mappings rim:n/a v2:CX.4 / EI-2-4 rim:II.root or Role.id.root servd:./IdentifierType
value	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.focus.identifier.value Short description The value that is unique Definition The portion of the identifier typically relevant to the user and which is unique within the context of the system. Comments If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General 123456 Mappings rim:n/a v2:CX.1 / EI.1 rim:II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root) servd:./Value
period	Σ I	0..1	Period	There are no (further) constraints on this element Element Id MessageHeader.focus.identifier.period Short description Time period when id is/was valid for use Definition Time period during which identifier is/was valid for use. Comments A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). Period is not used for a duration (a measure of elapsed time). See Duration. Data Type Period Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` per-1:If present, start SHALL have a lower value than end `start.hasValue().not() or end.hasValue().not() or (start <= end)` Mappings rim:n/a v2:DR rim:IVL<TS>[lowClosed="true" and highClosed="true"] or URG<TS>[lowClosed="true" and highClosed="true"] v2:CX.7 + CX.8 rim:Role.effectiveTime or implied by context servd:./StartDate and ./EndDate
assigner	Σ I	0..1	Reference(UK Core Organization)	There are no (further) constraints on this element Element Id MessageHeader.focus.identifier.assigner Short description Organization that issued id (may be just text) Definition Organization that issued/manages the identifier. Comments The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization. Data Type Reference(UK Core Organization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:CX.4 / (CX.4,CX.9,CX.10) rim:II.assigningAuthorityName but note that this is an improper use by the definition of the field. Also Role.scoper servd:./IdentifierIssuingAuthority
display	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.focus.display Short description Text alternative for the resource Definition Plain text narrative that identifies the resource in addition to the resource reference. Comments This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
definition	Σ	0..1	canonical(MessageDefinition)	There are no (further) constraints on this element Element Id MessageHeader.definition Short description Link to the definition for this message Definition Permanent link to the MessageDefinition for this message. Requirements Allows sender to define the expected contents of the message. Comments see Canonical References Data Type canonical(MessageDefinition) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:Not directly supported.

from MessageHeader

MessageHeader	I		MessageHeader	Element Id MessageHeader Short description A resource that describes a message that is exchanged between systems Definition The header for a FHIR Message exchange that is either requesting or responding to an action. The reference(s) that are the subject of the action as well as other information related to the action are typically transmitted in a bundle in which the MessageHeader resource instance is the first resource in the bundle. Messaging middleware systems are expected to use this `MessageHeader` resource to route, deliver and handle messages correctly. This profile is not tied to any specific transport/API requirement or clinical requirement. Intermediaries are not expected to perform detailed routing on clinical content. Some clinical information will be required for routing purposes and this will be held within `eventCoding` and `reason` sections as discussed in the Message Event section below. In circumstances where more detailed information is required for routing this MUST be carried in the relevant FHIR Resource in the payload only. For example, document types should be recorded in FHIR `DocumentReference.type` and health service/specialty type can be recorded in FHIR `Encounter.serviceType` or `DocumentReference.context.practiceSetting`. Systems involved in NHSDigital/UKCore messaging are expected to support this profile only, extensions or derived profiles are permitted but they may only have limited (internal) scope and will not be supported outside of this scope (e.g. externally). This resource SHOULD NOT be profiled to further define the contents of the resources and FHIR MessageDefinition MUST be used instead. Comments identifiers and message timings FHIR messages have two identifiers: the messageIdentifier of the Message (`Bundle.identifier`) and a messageId (`Bundle.id`) which is used in each transport channel . The messageId should be unique within a each message channel/stream. Whenever a message is resent, the messageIdentifier of the Bundle remains the same, but the messageId may change. The response message has its own unique messageIdentifier, the messageIdentifier of the request message can be referenced in the MessageHeader.response.identifier element. The `Bundle.identifier`, the messageIdentifier, MUST have a UUID value. Systems may chose to map X-Request-ID header to the `Bundle.id`, messageId. If both are supplied to a `$process-messge` endpoint it is recommended they hold the same values. MessageHeader can hold previous and extra messageId's in the {{link:https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-messageId}} Local Part/Addressing (sender and/or destination.receiver) When exchanging messages between organisations, local references SHOULD NOT be used for `sender` and `destination.receiver` references. Local references can make use of the Extension {{link:https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-LocalPart}}. Messages between Organisations should be directed to the Organisation. The receiving organisation will take responsibility for delivering to the local address. Sending organisations are not expected to be able to deliver to local entities in another organisation/domain/facility. This concept is similar to email addresses `local-part@domain` and also HL7 version 2 combination of `Sending/Receiving Application \| Sennding/Receiving Facility` in the MSH segment. In the example below, the destination is a clinic (A99968) which part of NHS Trust (RBA). Note also the destination endpoint is for the NHS Trust, who will route the message as required. `"destination": [ { "endpoint": "urn:nhs-uk:addressing:ods:RBA", "receiver": { "extension": [ { "url": "https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-LocalPart", "valueReference": { "identifier": { "system": "https://fhir.nhs.uk/Id/ods-organization-code", "value": "A99968" } } } ], "identifier": { "system": "https://fhir.nhs.uk/Id/ods-organization-code", "value": "RBA" }, "display": "TAUNTON AND SOMERSET NHS FOUNDATION TRUST" } } ],` example - Prescription, Pharmacy known {{render:nominatedPharmacy}} In the example below, the prescriber Taunton and Somerset Foundation Trust (RBA), is sending a message to The Simple Pharmacy (VNE51). The `destination.receiver` and `sender` are references to these organisations. This message is to be sent via the Electronic Prescription Service, the http address of EPS is held in `destination.endpoint`. Replies to this message can only be received by MESH and the `source.endpoint` is the MESH address of the sending organisation. "destination": [ { "endpoint": "https://sandbox.api.service.nhs.uk/electronic-prescriptions/$post-message", "receiver": { "identifier": { "system": "https://fhir.nhs.uk/Id/ods-organization-code", "value": "VNE51" }, "display": "The Simple Pharmacy" } } ], "sender": { "identifier": { "extension": [ { "url": "https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-LocalPart", "valueReference": { "identifier": { "system": "https://fhir.nhs.uk/Id/ods-organization-code", "value": "A99968" } } } ], "system": "https://fhir.nhs.uk/Id/ods-organization-code", "value": "RBA" }, "display": "TAUNTON AND SOMERSET NHS FOUNDATION TRUST" }, "source": { "endpoint": "urn:nhs-uk:addressing:ods:RBA" } EPS will now send this message to the pharmacy. This message is collected by the pharmacy using MESH and so the `destination.endpoint` is now the MESH address of the pharmacy. Replies to this message are sent to EPS and so the `source.endpoint` is now the http address of the EPS $process-message endpoint. "destination": [ { "endpoint": "urn:nhs-uk:addressing:ods:VNE51", "receiver": { "identifier": { "system": "https://fhir.nhs.uk/Id/ods-organization-code", "value": "VNE51" }, "display": "The Simple Pharmacy" } } ], "sender": { "extension": [ { "url": "https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-LocalPart", "valueReference": { "identifier": { "system": "https://fhir.nhs.uk/Id/ods-organization-code", "value": "A99968" } } } ], "identifier": { "system": "https://fhir.nhs.uk/Id/ods-organization-code", "value": "RBA" }, "display": "TAUNTON AND SOMERSET NHS FOUNDATION TRUST" }, "source": { "endpoint": "https://sandbox.api.service.nhs.uk/electronic-prescriptions/$post-message" } example - Prescription, Pharmacy not known {{render:noNominatedPharmacy}} In this example the destination is not known and the message is sent to NHS Digital (X26). "destination": [ { "endpoint": "https://sandbox.api.service.nhs.uk/electronic-prescriptions/$post-message", "receiver": { {{render:messageIDs}} In addition, a FHIR Message Bundle has two important timestamps: The time of sending the message is captured in the timestamp element The last time the message was updated (e.g. by storing or modification) is captured in the meta.lastUpdated element. ```json { "resourceType": "Bundle", "id": "884cfa4f-7a56-4be5-9592-783ef4f3992a", "meta": { "lastUpdated": "2020-11-02T01:43:30+00:00" }, "identifier": { "system": "https://tools.ietf.org/html/rfc4122", "value": "ad945a29-85f8-439a-b590-6789719adc16" }, "type": "message", "timestamp": "2020-11-02T01:43:30+00:00", "entry": [ { "fullUrl": "urn:uuid:311316d3-1de0-4f7c-8109-c950ead1c717", "resource": { "resourceType": "MessageHeader", "extension": [ { "url": "https://fhir.nhs.uk/StructureDefinition/Extension-Spine-MessageHeader-messageId", "valueIdentifier": { "system": "https://fhir.nhs.uk/Id/prescription-order-number", "value": "DC2C66-A1B2C3-23407B" } } ] From (source and sender) and To (destination) The From is contained in both the `sender` and `source` elements and the To is contained in the `destination` array. One source, sender and at least one destination MUST be present. Messages may be sent over multiple transmission legs (i.e. the first leg uses http and the second MESH). The contents of elements SHOULD reflect the current leg only. destination.endpoint source.endpoint MessageHeader.extension(messageId) Endpoints MUST point to valid endpoint uri's on each leg of the messages journey, they may not refer to inaccessible endpoints on other legs. See also the destination section below. Data Type MessageHeader Constraints dom-2:If the resource is contained in another resource, it SHALL NOT contain nested Resources `contained.contained.empty()` dom-4:If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated `contained.meta.versionId.empty() and contained.meta.lastUpdated.empty()` dom-3:If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource or SHALL refer to the containing resource `contained.where((('#'+id in (%resource.descendants().reference \| %resource.descendants().as(canonical) \| %resource.descendants().as(uri) \| %resource.descendants().as(url))) or descendants().where(reference = '#').exists() or descendants().where(as(canonical) = '#').exists() or descendants().where(as(canonical) = '#').exists()).not()).trace('unmatched', id).empty()` dom-6:A resource should have narrative for robust management text.`div`.exists() dom-5:If a resource is contained in another resource, it SHALL NOT have a security label `contained.meta.security.empty()` nhsd-11:replacementOf extension is required for update messages `event.code.where(substring($this.length()-6) = 'update').exists().not() or (event.code.where(substring($this.length()-6) = 'update').exists() and extension('https://fhir.nhs.uk/StructureDefinition/Extension-replacementOf').exists())` Mappings rim:Entity. Role, or Act v2:MSH / MSA / ERR rim:Message
extension	I	0..*	Extension	Element Id MessageHeader.extension Short description Additional content defined by implementations Alternate names extensions, user content Definition May be used to represent additional information that is not part of the basic definition of the resource. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Comments There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone. Data Type Extension Sliced: Unordered, Open, by url(Value) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ext-1:Must have either extensions or value[x], not both `extension.exists() != value.exists()` Mappings rim:n/a rim:N/A
messageHeaderInstruction	I	0..*	Extension(Coding)	There are no (further) constraints on this element Element Id MessageHeader.extension:messageHeaderInstruction Short description An extension to carry a specific instruction for receivers of the message. Alternate names extensions, user content Definition An extension to carry a specific instruction for receivers of the message. Comments There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone. Data Type Extension(Coding) Extension URL https://fhir.hl7.org.uk/StructureDefinition/Extension-UKCore-MessageHeaderInstruction Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ext-1:Must have either extensions or value[x], not both `extension.exists() != value.exists()` Mappings rim:n/a rim:N/A
replacementOf	S I	0..1	Extension(Identifier)	Element Id MessageHeader.extension:replacementOf Short description Optional Extensions Element Alternate names extensions, user content Definition If the message is an update or replaceOf a previous message, then this extension should reference the replaced FHIR Message (Bundle.identifier). `"extension": [ { "url": "https://fhir.nhs.uk/StructureDefinition/Extension-replacementOf", "valueIdentifier": { "system": "https://tools.ietf.org/html/rfc4122", "value": "334a3195-1f6c-497a-8efe-d272ca9c4e38" } } ],` Comments There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone. Data Type Extension(Identifier) Extension URL https://fhir.nhs.uk/StructureDefinition/Extension-replacementOf Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ext-1:Must have either extensions or value[x], not both `extension.exists() != value.exists()` Mappings rim:n/a rim:N/A
event[x]	S Σ	1..1	Binding	Element Id MessageHeader.event[x] Short description Code for the event this message represents or link to event definition Definition The main message type is held in the mandatory `eventCoding` section which can be subdivided by the optional `reason` codes. Every code MUST have a corresponding `MessageDefinition`. For example the event code `dispense-notification` has a MessageDefintion of https://fhir.nhs.uk/MessageDefinition/pharmacy-dispense. This definition lists the profiles and cardinality of the resources in the message. `eventCoding` and MessageDefintion define the structure of the message. `"eventCoding": { "system": "https://fhir.nhs.uk/CodeSystem/message-event", "code": "dispense-notification", "display": "Dispense Notification" }` Requirements Drives the behavior associated with this message. Comments The time of the event will be found in the focus resource. The time of the message will be found in Bundle.timestamp. Binding Message event NHSMessageEvents (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a w5:FiveWs.what[x] v2:MSH-9.2 rim:./payload[classCode="CACT" and moodCode="EVN" and isNormalAct()]/code[isNormalDatatype()]/code
eventCoding			Coding	Data Type Coding
system	Σ	1..1	uri	There are no (further) constraints on this element Element Id MessageHeader.event[x].system Short description Identity of the terminology system Definition The identification of the code system that defines the meaning of the symbol in the code. Requirements Need to be unambiguous about the source of the definition of the symbol. Comments The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should reference to some definition that establishes the system clearly and unambiguously. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE.3 rim:./codeSystem orim:*fhir:Coding.system rdfs:subPropertyOf dt:CDCoding.codeSystem
version	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.event[x].version Short description Version of the system - if relevant Definition The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured, and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged. Comments Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE.7 rim:./codeSystemVersion orim:*fhir:Coding.version rdfs:subPropertyOf dt:CDCoding.codeSystemVersion
code	Σ	1..1	code	There are no (further) constraints on this element Element Id MessageHeader.event[x].code Short description Symbol in syntax defined by the system Definition A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination). Requirements Need to refer to a particular code in the system. Comments Note that FHIR strings SHALL NOT exceed 1MB in size Data Type code Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE.1 rim:./code orim:*fhir:Coding.code rdfs:subPropertyOf dt:CDCoding.code
display	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.event[x].display Short description Representation defined by the system Definition A representation of the meaning of the code in the system, following the rules of the system. Requirements Need to be able to carry a human-readable meaning of the code for readers that do not know the system. Comments Note that FHIR strings SHALL NOT exceed 1MB in size Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE.2 - but note this is not well followed rim:CV.displayName orim:*fhir:Coding.display rdfs:subPropertyOf dt:CDCoding.displayName
userSelected	Σ	0..1	boolean	There are no (further) constraints on this element Element Id MessageHeader.event[x].userSelected Short description If this coding was chosen directly by the user Definition Indicates that this coding was chosen by a user directly - e.g. off a pick list of available items (codes or displays). Requirements This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing. Comments Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely. Data Type boolean Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:Sometimes implied by being first rim:CD.codingRationale orim:fhir:Coding.userSelected fhir:mapsTo dt:CDCoding.codingRationale. fhir:Coding.userSelected fhir:hasMap fhir:Coding.userSelected.map. fhir:Coding.userSelected.map a fhir:Map; fhir:target dt:CDCoding.codingRationale. fhir:Coding.userSelected\#true a [ fhir:source "true"; fhir:target dt:CDCoding.codingRationale\#O ]
destination	S Σ	0..*	BackboneElement	Element Id MessageHeader.destination Short description Message destination application(s) Definition Lists all the destinations where message is be delivered to. The recipient of a message takes the responsibility of delivering to all the `destination.endpoint`s. Similarly the sender MUST NOT include destination's the recipient can not deliver to, these destinations MUST be removed from the message. Additional rules for endpoint can be found in the source section below. Requirements Indicates where message is to be sent for routing purposes. Allows verification of "am I the intended recipient". `"destination": [ { "endpoint": "urn:nhs-uk:addressing:mesh:Y90638OT002", "receiver": { "identifier": { "system": "https://fhir.nhs.uk/Id/ods-organization-code", "value": "Y9063" } } } ]` Comments There SHOULD be at least one destination, but in some circumstances, the source system is unaware of any particular destination system. Data Type BackboneElement Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a w5:FiveWs.subject[x] rim:./communicationFunction[typeCode="RCV"] w5:FiveWs.subject
name	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.destination.name Short description Name of system Definition Human-readable name for the target system. Requirements May be used for routing of response and/or to support audit. Comments Note that FHIR strings SHALL NOT exceed 1MB in size Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:MSH-5 rim:unique(./entity[determinerCode="INST" and (classCode=("DEV", "PSN", "ORG"]/name[type='ST' and isNormalDatatype()])
target	Σ I	0..1	Reference(UK Core Device)	There are no (further) constraints on this element Element Id MessageHeader.destination.target Short description Particular delivery destination within the destination Definition Identifies the target end system in situations where the initial message transmission is to an intermediary system. Requirements Supports multi-hop routing. Comments References SHALL be a reference to an actual FHIR resource, and SHALL be resolveable (allowing for access control, temporary unavailability, etc.). Resolution can be either by retrieval from the URL, or, where applicable by resource type, by treating an absolute reference as a canonical URL and looking it up in a local registry/repository. Data Type Reference(UK Core Device) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) rim:unique(./entity[determinerCode="INST" and (classCode=("DEV", "PSN", "ORG"]
reference	Σ I	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.destination.target.reference Short description Literal reference, Relative, internal or absolute URL Definition A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources. Comments Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
type	Σ	0..1	uriBinding	There are no (further) constraints on this element Element Id MessageHeader.destination.target.type Short description Type the reference refers to (e.g. "Patient") Definition The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent. The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources). Comments This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified. Data Type uri Binding Aa resource (or, for logical models, the URI of the logical model). ResourceType (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
identifier	Σ	0..1	Identifier	There are no (further) constraints on this element Element Id MessageHeader.destination.target.identifier Short description Logical reference, when literal reference is not known Definition An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference. Comments When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation\|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any). Data Type Identifier Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CX / EI (occasionally, more often EI maps to a resource id or a URL) rim:II - The Identifier class is a little looser than the v3 type II because it allows URIs as well as registered OIDs or GUIDs. Also maps to Role[classCode=IDENT] servd:Identifier rim:.identifier
use	Σ ?!	0..1	codeBinding	There are no (further) constraints on this element Element Id MessageHeader.destination.target.identifier.use Short description usual \| official \| temp \| secondary \| old (If known) Definition The purpose of this identifier. Requirements Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers. Comments Applications can assume that an identifier is permanent unless it explicitly says that it is temporary. Data Type code Binding Identifies the purpose for this identifier, if known . IdentifierUse (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:N/A rim:Role.code or implied by context
type	Σ	0..1	CodeableConceptBinding	There are no (further) constraints on this element Element Id MessageHeader.destination.target.identifier.type Short description Description of identifier Definition A coded type for the identifier that can be used to determine which identifier to use for a specific purpose. Requirements Allows users to make use of identifiers when the identifier system is not known. Comments This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type. Data Type CodeableConcept Binding A coded type for an identifier that can be used to determine which identifier to use for a specific purpose. Identifier Type Codes (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD v2:CX.5 rim:Role.code or implied by context
system	Σ	0..1	uri	There are no (further) constraints on this element Element Id MessageHeader.destination.target.identifier.system Short description The namespace for the identifier value Definition Establishes the namespace for the value - that is, a URL that describes a set values that are unique. Requirements There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers. Comments Identifier.system is always case sensitive. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General http://www.acme.com/identifiers/patient Mappings rim:n/a v2:CX.4 / EI-2-4 rim:II.root or Role.id.root servd:./IdentifierType
value	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.destination.target.identifier.value Short description The value that is unique Definition The portion of the identifier typically relevant to the user and which is unique within the context of the system. Comments If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General 123456 Mappings rim:n/a v2:CX.1 / EI.1 rim:II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root) servd:./Value
period	Σ I	0..1	Period	There are no (further) constraints on this element Element Id MessageHeader.destination.target.identifier.period Short description Time period when id is/was valid for use Definition Time period during which identifier is/was valid for use. Comments A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). Period is not used for a duration (a measure of elapsed time). See Duration. Data Type Period Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` per-1:If present, start SHALL have a lower value than end `start.hasValue().not() or end.hasValue().not() or (start <= end)` Mappings rim:n/a v2:DR rim:IVL<TS>[lowClosed="true" and highClosed="true"] or URG<TS>[lowClosed="true" and highClosed="true"] v2:CX.7 + CX.8 rim:Role.effectiveTime or implied by context servd:./StartDate and ./EndDate
assigner	Σ I	0..1	Reference(UK Core Organization)	There are no (further) constraints on this element Element Id MessageHeader.destination.target.identifier.assigner Short description Organization that issued id (may be just text) Definition Organization that issued/manages the identifier. Comments The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization. Data Type Reference(UK Core Organization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:CX.4 / (CX.4,CX.9,CX.10) rim:II.assigningAuthorityName but note that this is an improper use by the definition of the field. Also Role.scoper servd:./IdentifierIssuingAuthority
display	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.destination.target.display Short description Text alternative for the resource Definition Plain text narrative that identifies the resource in addition to the resource reference. Comments This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
endpoint	Σ	1..1	url	There are no (further) constraints on this element Element Id MessageHeader.destination.endpoint Short description Actual destination address or id Definition Indicates where the message should be routed to. Requirements Identifies where to route the message. Comments The id may be a non-resolvable URI for systems that do not use standard network-based addresses. Data Type url Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:MSH-25 (or MSH-6) rim:./telecom
receiver	Σ I	1..1	Reference(NHSDigitalPractitionerRole \| NHSDigitalPractitioner \| NHSDigitalOrganization)	Element Id MessageHeader.destination.receiver Short description Intended "real-world" recipient for the data Definition Allows data conveyed by a message to be addressed to a particular person or department when routing to a specific application isn't sufficient. Requirements Allows routing beyond just the application level. Comments References SHALL be a reference to an actual FHIR resource, and SHALL be resolveable (allowing for access control, temporary unavailability, etc.). Resolution can be either by retrieval from the URL, or, where applicable by resource type, by treating an absolute reference as a canonical URL and looking it up in a local registry/repository. Data Type Reference(NHSDigitalPractitionerRole \| NHSDigitalPractitioner \| NHSDigitalOrganization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) w5:FiveWs.subject[x] v2:PRT-5:PRT-4='WAYR' / PRT-8:PRT-4='WAYR' rim:Not directly supported. Could be shared using attentionLine.value with an appropriate keyWordText w5:FiveWs.subject
extension	I	0..*	Extension	Element Id MessageHeader.destination.receiver.extension Short description Additional content defined by implementations Alternate names extensions, user content Definition May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Comments There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone. Data Type Extension Sliced: Unordered, Open, by url(Value) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ext-1:Must have either extensions or value[x], not both `extension.exists() != value.exists()` Mappings rim:n/a rim:N/A
receiverLocalPart	I	0..1	Extension(Reference(NHSDigitalHealthcareService \| NHSDigitalPractitionerRole \| NHSDigitalPractitioner))	Element Id MessageHeader.destination.receiver.extension:receiverLocalPart Short description Optional Extensions Element Alternate names extensions, user content Definition Optional Extension Element - found in all resources. Comments There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone. Data Type Extension(Reference(NHSDigitalHealthcareService \| NHSDigitalPractitionerRole \| NHSDigitalPractitioner)) Extension URL https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-LocalPart Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ext-1:Must have either extensions or value[x], not both `extension.exists() != value.exists()` Mappings rim:n/a rim:N/A
reference	Σ I	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.destination.receiver.reference Short description Literal reference, Relative, internal or absolute URL Definition A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources. Comments Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
type	Σ	0..1	uriBinding	There are no (further) constraints on this element Element Id MessageHeader.destination.receiver.type Short description Type the reference refers to (e.g. "Patient") Definition The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent. The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources). Comments This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified. Data Type uri Binding Aa resource (or, for logical models, the URI of the logical model). ResourceType (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
identifier	Σ	1..1	Identifier	There are no (further) constraints on this element Element Id MessageHeader.destination.receiver.identifier Short description Logical reference, when literal reference is not known Definition An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference. Comments When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation\|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any). Data Type Identifier Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CX / EI (occasionally, more often EI maps to a resource id or a URL) rim:II - The Identifier class is a little looser than the v3 type II because it allows URIs as well as registered OIDs or GUIDs. Also maps to Role[classCode=IDENT] servd:Identifier rim:.identifier
use	Σ ?!	0..1	codeBinding	There are no (further) constraints on this element Element Id MessageHeader.destination.receiver.identifier.use Short description usual \| official \| temp \| secondary \| old (If known) Definition The purpose of this identifier. Requirements Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers. Comments Applications can assume that an identifier is permanent unless it explicitly says that it is temporary. Data Type code Binding Identifies the purpose for this identifier, if known . IdentifierUse (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:N/A rim:Role.code or implied by context
type	Σ	0..1	CodeableConceptBinding	There are no (further) constraints on this element Element Id MessageHeader.destination.receiver.identifier.type Short description Description of identifier Definition A coded type for the identifier that can be used to determine which identifier to use for a specific purpose. Requirements Allows users to make use of identifiers when the identifier system is not known. Comments This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type. Data Type CodeableConcept Binding A coded type for an identifier that can be used to determine which identifier to use for a specific purpose. Identifier Type Codes (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD v2:CX.5 rim:Role.code or implied by context
system	Σ	1..1	uri	There are no (further) constraints on this element Element Id MessageHeader.destination.receiver.identifier.system Short description The namespace for the identifier value Definition Establishes the namespace for the value - that is, a URL that describes a set values that are unique. Requirements There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers. Comments Identifier.system is always case sensitive. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General http://www.acme.com/identifiers/patient Mappings rim:n/a v2:CX.4 / EI-2-4 rim:II.root or Role.id.root servd:./IdentifierType
value	Σ	1..1	string	There are no (further) constraints on this element Element Id MessageHeader.destination.receiver.identifier.value Short description The value that is unique Definition The portion of the identifier typically relevant to the user and which is unique within the context of the system. Comments If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General 123456 Mappings rim:n/a v2:CX.1 / EI.1 rim:II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root) servd:./Value
period	Σ I	0..1	Period	There are no (further) constraints on this element Element Id MessageHeader.destination.receiver.identifier.period Short description Time period when id is/was valid for use Definition Time period during which identifier is/was valid for use. Comments A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). Period is not used for a duration (a measure of elapsed time). See Duration. Data Type Period Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` per-1:If present, start SHALL have a lower value than end `start.hasValue().not() or end.hasValue().not() or (start <= end)` Mappings rim:n/a v2:DR rim:IVL<TS>[lowClosed="true" and highClosed="true"] or URG<TS>[lowClosed="true" and highClosed="true"] v2:CX.7 + CX.8 rim:Role.effectiveTime or implied by context servd:./StartDate and ./EndDate
assigner	Σ I	0..1	Reference(UK Core Organization)	There are no (further) constraints on this element Element Id MessageHeader.destination.receiver.identifier.assigner Short description Organization that issued id (may be just text) Definition Organization that issued/manages the identifier. Comments The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization. Data Type Reference(UK Core Organization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:CX.4 / (CX.4,CX.9,CX.10) rim:II.assigningAuthorityName but note that this is an improper use by the definition of the field. Also Role.scoper servd:./IdentifierIssuingAuthority
display	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.destination.receiver.display Short description Text alternative for the resource Definition Plain text narrative that identifies the resource in addition to the resource reference. Comments This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
sender	S Σ I	0..1	Reference(NHSDigitalPractitionerRole \| NHSDigitalPractitioner \| NHSDigitalOrganization)	Element Id MessageHeader.sender Short description Real world sender of the message Definition The current requirement in NHS Digital API's is to rely on the Access Tokens and Audit (JWT) for sender details. For use outside of NHS Digital it is recommended this is populated with either the Organisation ODS code or the Practitioner's professional code. `"sender": { "identifier": { "system": "https://fhir.nhs.uk/Id/ods-organization-code", "value": "VNE51" } }` Requirements Allows routing beyond just the application level. Comments Use case is for where a (trusted) sending system is responsible for multiple organizations, and therefore cannot differentiate based on source endpoint / authentication alone. Data Type Reference(NHSDigitalPractitionerRole \| NHSDigitalPractitioner \| NHSDigitalOrganization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) w5:FiveWs.subject[x] v2:PRT-5:PRT-4='WAYR' / PRT-8:PRT-4='WAYR' rim:Not directly supported. Could be shared using attentionLine.value with an appropriate keyWordText w5:FiveWs.subject
extension	I	0..*	Extension	Element Id MessageHeader.sender.extension Short description Additional content defined by implementations Alternate names extensions, user content Definition May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Comments There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone. Data Type Extension Sliced: Unordered, Open, by url(Value) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ext-1:Must have either extensions or value[x], not both `extension.exists() != value.exists()` Mappings rim:n/a rim:N/A
senderLocalPart	I	0..1	Extension(Reference(NHSDigitalHealthcareService \| NHSDigitalPractitionerRole \| NHSDigitalPractitioner))	Element Id MessageHeader.sender.extension:senderLocalPart Short description Optional Extensions Element Alternate names extensions, user content Definition Optional Extension Element - found in all resources. Comments There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone. Data Type Extension(Reference(NHSDigitalHealthcareService \| NHSDigitalPractitionerRole \| NHSDigitalPractitioner)) Extension URL https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-LocalPart Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ext-1:Must have either extensions or value[x], not both `extension.exists() != value.exists()` Mappings rim:n/a rim:N/A
reference	Σ I	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.sender.reference Short description Literal reference, Relative, internal or absolute URL Definition A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources. Comments Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
type	Σ	0..1	uriBinding	There are no (further) constraints on this element Element Id MessageHeader.sender.type Short description Type the reference refers to (e.g. "Patient") Definition The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent. The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources). Comments This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified. Data Type uri Binding Aa resource (or, for logical models, the URI of the logical model). ResourceType (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
identifier	S Σ	1..1	Identifier	There are no (further) constraints on this element Element Id MessageHeader.sender.identifier Short description Logical reference, when literal reference is not known Definition An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference. Comments When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation\|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any). Data Type Identifier Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CX / EI (occasionally, more often EI maps to a resource id or a URL) rim:II - The Identifier class is a little looser than the v3 type II because it allows URIs as well as registered OIDs or GUIDs. Also maps to Role[classCode=IDENT] servd:Identifier rim:.identifier
use	Σ ?!	0..1	codeBinding	There are no (further) constraints on this element Element Id MessageHeader.sender.identifier.use Short description usual \| official \| temp \| secondary \| old (If known) Definition The purpose of this identifier. Requirements Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers. Comments Applications can assume that an identifier is permanent unless it explicitly says that it is temporary. Data Type code Binding Identifies the purpose for this identifier, if known . IdentifierUse (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:N/A rim:Role.code or implied by context
type	Σ	0..1	CodeableConceptBinding	There are no (further) constraints on this element Element Id MessageHeader.sender.identifier.type Short description Description of identifier Definition A coded type for the identifier that can be used to determine which identifier to use for a specific purpose. Requirements Allows users to make use of identifiers when the identifier system is not known. Comments This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type. Data Type CodeableConcept Binding A coded type for an identifier that can be used to determine which identifier to use for a specific purpose. Identifier Type Codes (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD v2:CX.5 rim:Role.code or implied by context
system	Σ	1..1	uri	There are no (further) constraints on this element Element Id MessageHeader.sender.identifier.system Short description The namespace for the identifier value Definition Establishes the namespace for the value - that is, a URL that describes a set values that are unique. Requirements There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers. Comments Identifier.system is always case sensitive. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General http://www.acme.com/identifiers/patient Mappings rim:n/a v2:CX.4 / EI-2-4 rim:II.root or Role.id.root servd:./IdentifierType
value	Σ	1..1	string	There are no (further) constraints on this element Element Id MessageHeader.sender.identifier.value Short description The value that is unique Definition The portion of the identifier typically relevant to the user and which is unique within the context of the system. Comments If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General 123456 Mappings rim:n/a v2:CX.1 / EI.1 rim:II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root) servd:./Value
period	Σ I	0..1	Period	There are no (further) constraints on this element Element Id MessageHeader.sender.identifier.period Short description Time period when id is/was valid for use Definition Time period during which identifier is/was valid for use. Comments A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). Period is not used for a duration (a measure of elapsed time). See Duration. Data Type Period Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` per-1:If present, start SHALL have a lower value than end `start.hasValue().not() or end.hasValue().not() or (start <= end)` Mappings rim:n/a v2:DR rim:IVL<TS>[lowClosed="true" and highClosed="true"] or URG<TS>[lowClosed="true" and highClosed="true"] v2:CX.7 + CX.8 rim:Role.effectiveTime or implied by context servd:./StartDate and ./EndDate
assigner	Σ I	0..1	Reference(UK Core Organization)	There are no (further) constraints on this element Element Id MessageHeader.sender.identifier.assigner Short description Organization that issued id (may be just text) Definition Organization that issued/manages the identifier. Comments The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization. Data Type Reference(UK Core Organization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:CX.4 / (CX.4,CX.9,CX.10) rim:II.assigningAuthorityName but note that this is an improper use by the definition of the field. Also Role.scoper servd:./IdentifierIssuingAuthority
display	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.sender.display Short description Text alternative for the resource Definition Plain text narrative that identifies the resource in addition to the resource reference. Comments This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
enterer	Σ I	0..1	Reference(NHSDigitalPractitionerRole \| NHSDigitalPractitioner)	Element Id MessageHeader.enterer Short description The source of the data entry Definition The person or device that performed the data entry leading to this message. When there is more than one candidate, pick the most proximal to the message. Can provide other enterers in extensions. Requirements Need to know for audit/traceback requirements and possibly for authorization. Comments Usually only for the request but can be used in a response. Data Type Reference(NHSDigitalPractitionerRole \| NHSDigitalPractitioner) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) w5:FiveWs.author v2:EVN-5 / ORC-10 / PRT-5:PRT-4='EP' / ROL where ROL.3 is EP or ORC.10 rim:unique(./controlAct[classCode="CACT" and classCode="EVN" and isNormalAct()]/participation[typeCode="ENT" and isNormalParticipation]/role[classCode="ASSIGNED" and isNormalRole()]/player[isNormalEntity() and classCode=("DEV", "PSN") and determinerCode="INST"])
reference	Σ I	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.enterer.reference Short description Literal reference, Relative, internal or absolute URL Definition A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources. Comments Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
type	Σ	0..1	uriBinding	There are no (further) constraints on this element Element Id MessageHeader.enterer.type Short description Type the reference refers to (e.g. "Patient") Definition The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent. The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources). Comments This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified. Data Type uri Binding Aa resource (or, for logical models, the URI of the logical model). ResourceType (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
identifier	Σ	0..1	Identifier	There are no (further) constraints on this element Element Id MessageHeader.enterer.identifier Short description Logical reference, when literal reference is not known Definition An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference. Comments When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation\|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any). Data Type Identifier Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CX / EI (occasionally, more often EI maps to a resource id or a URL) rim:II - The Identifier class is a little looser than the v3 type II because it allows URIs as well as registered OIDs or GUIDs. Also maps to Role[classCode=IDENT] servd:Identifier rim:.identifier
use	Σ ?!	0..1	codeBinding	There are no (further) constraints on this element Element Id MessageHeader.enterer.identifier.use Short description usual \| official \| temp \| secondary \| old (If known) Definition The purpose of this identifier. Requirements Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers. Comments Applications can assume that an identifier is permanent unless it explicitly says that it is temporary. Data Type code Binding Identifies the purpose for this identifier, if known . IdentifierUse (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:N/A rim:Role.code or implied by context
type	Σ	0..1	CodeableConceptBinding	There are no (further) constraints on this element Element Id MessageHeader.enterer.identifier.type Short description Description of identifier Definition A coded type for the identifier that can be used to determine which identifier to use for a specific purpose. Requirements Allows users to make use of identifiers when the identifier system is not known. Comments This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type. Data Type CodeableConcept Binding A coded type for an identifier that can be used to determine which identifier to use for a specific purpose. Identifier Type Codes (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD v2:CX.5 rim:Role.code or implied by context
system	Σ	0..1	uri	There are no (further) constraints on this element Element Id MessageHeader.enterer.identifier.system Short description The namespace for the identifier value Definition Establishes the namespace for the value - that is, a URL that describes a set values that are unique. Requirements There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers. Comments Identifier.system is always case sensitive. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General http://www.acme.com/identifiers/patient Mappings rim:n/a v2:CX.4 / EI-2-4 rim:II.root or Role.id.root servd:./IdentifierType
value	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.enterer.identifier.value Short description The value that is unique Definition The portion of the identifier typically relevant to the user and which is unique within the context of the system. Comments If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General 123456 Mappings rim:n/a v2:CX.1 / EI.1 rim:II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root) servd:./Value
period	Σ I	0..1	Period	There are no (further) constraints on this element Element Id MessageHeader.enterer.identifier.period Short description Time period when id is/was valid for use Definition Time period during which identifier is/was valid for use. Comments A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). Period is not used for a duration (a measure of elapsed time). See Duration. Data Type Period Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` per-1:If present, start SHALL have a lower value than end `start.hasValue().not() or end.hasValue().not() or (start <= end)` Mappings rim:n/a v2:DR rim:IVL<TS>[lowClosed="true" and highClosed="true"] or URG<TS>[lowClosed="true" and highClosed="true"] v2:CX.7 + CX.8 rim:Role.effectiveTime or implied by context servd:./StartDate and ./EndDate
assigner	Σ I	0..1	Reference(UK Core Organization)	There are no (further) constraints on this element Element Id MessageHeader.enterer.identifier.assigner Short description Organization that issued id (may be just text) Definition Organization that issued/manages the identifier. Comments The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization. Data Type Reference(UK Core Organization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:CX.4 / (CX.4,CX.9,CX.10) rim:II.assigningAuthorityName but note that this is an improper use by the definition of the field. Also Role.scoper servd:./IdentifierIssuingAuthority
display	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.enterer.display Short description Text alternative for the resource Definition Plain text narrative that identifies the resource in addition to the resource reference. Comments This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
author	Σ I	0..1	Reference(NHSDigitalPractitionerRole \| NHSDigitalPractitioner)	Element Id MessageHeader.author Short description The source of the decision Definition If present, this SHOULD be an identifier reference to a `Practitioner` or `PractitionerRole`. Internal references to resources should NOT be used. `"author": { "type": "PractitionerRole", "identifier": { "system": "https://fhir.nhs.uk/Id/sds-role-profile-id", "value": "100102238986" }, "display": "DR ALI" },` Requirements Need to know for audit/traceback requirements and possibly for authorization. Comments Usually only for the request but can be used in a response. Data Type Reference(NHSDigitalPractitionerRole \| NHSDigitalPractitioner) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) w5:FiveWs.author v2:ORC-19 / PRT-5:PRT-4='AUT' / ROL where ROL.3 is IP or ORC.12 rim:unique(./controlAct[classCode="CACT" and classCode="EVN" and isNormalAct()]/participation[isHighest(priorityCode) and typeCode="AUT" and isNormalParticipation]/role[classCode="ASSIGNED" and isNormalRole()]/player[isNormalEntity() and classCode=("DEV", "PSN") and determinerCode="INST"])
reference	Σ I	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.author.reference Short description Literal reference, Relative, internal or absolute URL Definition A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources. Comments Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
type	Σ	0..1	uriBinding	There are no (further) constraints on this element Element Id MessageHeader.author.type Short description Type the reference refers to (e.g. "Patient") Definition The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent. The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources). Comments This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified. Data Type uri Binding Aa resource (or, for logical models, the URI of the logical model). ResourceType (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
identifier	Σ	1..1	Identifier	There are no (further) constraints on this element Element Id MessageHeader.author.identifier Short description Logical reference, when literal reference is not known Definition An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference. Comments When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation\|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any). Data Type Identifier Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CX / EI (occasionally, more often EI maps to a resource id or a URL) rim:II - The Identifier class is a little looser than the v3 type II because it allows URIs as well as registered OIDs or GUIDs. Also maps to Role[classCode=IDENT] servd:Identifier rim:.identifier
use	Σ ?!	0..1	codeBinding	There are no (further) constraints on this element Element Id MessageHeader.author.identifier.use Short description usual \| official \| temp \| secondary \| old (If known) Definition The purpose of this identifier. Requirements Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers. Comments Applications can assume that an identifier is permanent unless it explicitly says that it is temporary. Data Type code Binding Identifies the purpose for this identifier, if known . IdentifierUse (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:N/A rim:Role.code or implied by context
type	Σ	0..1	CodeableConceptBinding	There are no (further) constraints on this element Element Id MessageHeader.author.identifier.type Short description Description of identifier Definition A coded type for the identifier that can be used to determine which identifier to use for a specific purpose. Requirements Allows users to make use of identifiers when the identifier system is not known. Comments This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type. Data Type CodeableConcept Binding A coded type for an identifier that can be used to determine which identifier to use for a specific purpose. Identifier Type Codes (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD v2:CX.5 rim:Role.code or implied by context
system	Σ	1..1	uri	There are no (further) constraints on this element Element Id MessageHeader.author.identifier.system Short description The namespace for the identifier value Definition Establishes the namespace for the value - that is, a URL that describes a set values that are unique. Requirements There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers. Comments Identifier.system is always case sensitive. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General http://www.acme.com/identifiers/patient Mappings rim:n/a v2:CX.4 / EI-2-4 rim:II.root or Role.id.root servd:./IdentifierType
value	Σ	1..1	string	There are no (further) constraints on this element Element Id MessageHeader.author.identifier.value Short description The value that is unique Definition The portion of the identifier typically relevant to the user and which is unique within the context of the system. Comments If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General 123456 Mappings rim:n/a v2:CX.1 / EI.1 rim:II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root) servd:./Value
period	Σ I	0..1	Period	There are no (further) constraints on this element Element Id MessageHeader.author.identifier.period Short description Time period when id is/was valid for use Definition Time period during which identifier is/was valid for use. Comments A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). Period is not used for a duration (a measure of elapsed time). See Duration. Data Type Period Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` per-1:If present, start SHALL have a lower value than end `start.hasValue().not() or end.hasValue().not() or (start <= end)` Mappings rim:n/a v2:DR rim:IVL<TS>[lowClosed="true" and highClosed="true"] or URG<TS>[lowClosed="true" and highClosed="true"] v2:CX.7 + CX.8 rim:Role.effectiveTime or implied by context servd:./StartDate and ./EndDate
assigner	Σ I	0..1	Reference(UK Core Organization)	There are no (further) constraints on this element Element Id MessageHeader.author.identifier.assigner Short description Organization that issued id (may be just text) Definition Organization that issued/manages the identifier. Comments The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization. Data Type Reference(UK Core Organization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:CX.4 / (CX.4,CX.9,CX.10) rim:II.assigningAuthorityName but note that this is an improper use by the definition of the field. Also Role.scoper servd:./IdentifierIssuingAuthority
display	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.author.display Short description Text alternative for the resource Definition Plain text narrative that identifies the resource in addition to the resource reference. Comments This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
source	S Σ	1..1	BackboneElement	Element Id MessageHeader.source Short description Message source application Definition `source.endpoint` is required and MUST indicate the address where replies are to be sent. For responses to be received via http this will be the address of the `$process-message` endpoint. E.g. `https://fhir.hospitaltrust.nhs.uk/$process-message` For MESH this will follow ITK2.2 MESH Transport Requirements for ITK Routing. E.g. the MESH Endpoint for Organisation B80310 `"source": { "endpoint": "urn:nhs-uk:addressing:mesh:Y90638OT001" }` Requirements Allows replies, supports audit. Data Type BackboneElement Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a w5:FiveWs.actor rim:unique(./communicationFunction[typeCode="SND"])
name	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.source.name Short description Name of system Definition Human-readable name for the source system. Requirements May be used to support audit. Comments Note that FHIR strings SHALL NOT exceed 1MB in size Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:MSH-3 rim:unique(./entity[determinerCode="INST" and classCode="DEV"]/name[type='ST' and isNormalDatatype()])
software	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.source.software Short description Name of software running the system Definition May include configuration or other information useful in debugging. Requirements Supports audit and possibly interface engine behavior. Comments Note that FHIR strings SHALL NOT exceed 1MB in size Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:SFT-3 ( +SFT-1) rim:unique(./entity[determinerCode="INST" and classCode="DEV"]/softwareName[isNormalDatatype()])
version	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.source.version Short description Version of software running Definition Can convey versions of multiple systems in situations where a message passes through multiple hands. Requirements Supports audit and possibly interface engine behavior. Comments Note that FHIR strings SHALL NOT exceed 1MB in size Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:SFT-2 rim:(Not supported)
contact	Σ I	0..1	ContactPoint	There are no (further) constraints on this element Element Id MessageHeader.source.contact Short description Human contact for problems Definition An e-mail, phone, website or other contact point to use to resolve issues with message communications. Requirements Allows escalation of technical issues. Data Type ContactPoint Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` cpt-2:A system is required if a value is provided. `value.empty() or system.exists()` Mappings rim:n/a v2:XTN rim:TEL servd:ContactPoint v2:(MSH-22?) rim:unique(./entity[determinerCode="INST" and classCode="DEV"]/scopesRole[normalRole() and classCode="CON" and layer[classCode="PSN"]/telecom[isNormalDatatype()])
endpoint	Σ	1..1	url	There are no (further) constraints on this element Element Id MessageHeader.source.endpoint Short description Actual message source address or id Definition Identifies the routing target to send acknowledgements to. Requirements Identifies where to send responses, may influence security permissions. Comments The id may be a non-resolvable URI for systems that do not use standard network-based addresses. Data Type url Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:MSH-24 rim:./telecom[isNormalDatatype()]
responsible	Σ I	0..1	Reference(NHSDigitalPractitioner \| NHSDigitalOrganization)	Element Id MessageHeader.responsible Short description Final responsibility for event Definition The person or organization that accepts overall responsibility for the contents of the message. The implication is that the message event happened under the policies of the responsible party. Requirements Need to know for audit/traceback requirements and possibly for authorization. Comments Usually only for the request but can be used in a response. Data Type Reference(NHSDigitalPractitioner \| NHSDigitalOrganization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) w5:FiveWs.witness v2:ORC-12 / PRT-5:PRT-4='OP' / PRT-8:PRT-4='OP' / ROL where ROL.3 is RO or ORC.11 rim:unique(./controlAct[classCode="CACT" and classCode="EVN" and isNormalAct()]/participation[isHighest(priorityCode) and typeCode="RESP" and isNormalParticipation]/role[classCode="ASSIGNED" and isNormalRole()]/player[isNormalEntity() and classCode="PSN" and determinerCode="INST"] or ./controlAct[classCode="CACT" and classCode="EVN" and isNormalAct()]/participation[isHighest(priorityCode) and typeCode="RESP" and isNormalParticipation]/role[classCode="ASSIGNED" and isNormalRole()]/scoper[isNormalEntity() and classCode="ORG" and determinerCode="INST"])
reference	Σ I	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.responsible.reference Short description Literal reference, Relative, internal or absolute URL Definition A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources. Comments Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
type	Σ	0..1	uriBinding	There are no (further) constraints on this element Element Id MessageHeader.responsible.type Short description Type the reference refers to (e.g. "Patient") Definition The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent. The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources). Comments This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified. Data Type uri Binding Aa resource (or, for logical models, the URI of the logical model). ResourceType (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
identifier	Σ	1..1	Identifier	There are no (further) constraints on this element Element Id MessageHeader.responsible.identifier Short description Logical reference, when literal reference is not known Definition An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference. Comments When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation\|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any). Data Type Identifier Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CX / EI (occasionally, more often EI maps to a resource id or a URL) rim:II - The Identifier class is a little looser than the v3 type II because it allows URIs as well as registered OIDs or GUIDs. Also maps to Role[classCode=IDENT] servd:Identifier rim:.identifier
use	Σ ?!	0..1	codeBinding	There are no (further) constraints on this element Element Id MessageHeader.responsible.identifier.use Short description usual \| official \| temp \| secondary \| old (If known) Definition The purpose of this identifier. Requirements Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers. Comments Applications can assume that an identifier is permanent unless it explicitly says that it is temporary. Data Type code Binding Identifies the purpose for this identifier, if known . IdentifierUse (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:N/A rim:Role.code or implied by context
type	Σ	0..1	CodeableConceptBinding	There are no (further) constraints on this element Element Id MessageHeader.responsible.identifier.type Short description Description of identifier Definition A coded type for the identifier that can be used to determine which identifier to use for a specific purpose. Requirements Allows users to make use of identifiers when the identifier system is not known. Comments This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type. Data Type CodeableConcept Binding A coded type for an identifier that can be used to determine which identifier to use for a specific purpose. Identifier Type Codes (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD v2:CX.5 rim:Role.code or implied by context
system	Σ	1..1	uri	There are no (further) constraints on this element Element Id MessageHeader.responsible.identifier.system Short description The namespace for the identifier value Definition Establishes the namespace for the value - that is, a URL that describes a set values that are unique. Requirements There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers. Comments Identifier.system is always case sensitive. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General http://www.acme.com/identifiers/patient Mappings rim:n/a v2:CX.4 / EI-2-4 rim:II.root or Role.id.root servd:./IdentifierType
value	Σ	1..1	string	There are no (further) constraints on this element Element Id MessageHeader.responsible.identifier.value Short description The value that is unique Definition The portion of the identifier typically relevant to the user and which is unique within the context of the system. Comments If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General 123456 Mappings rim:n/a v2:CX.1 / EI.1 rim:II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root) servd:./Value
period	Σ I	0..1	Period	There are no (further) constraints on this element Element Id MessageHeader.responsible.identifier.period Short description Time period when id is/was valid for use Definition Time period during which identifier is/was valid for use. Comments A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). Period is not used for a duration (a measure of elapsed time). See Duration. Data Type Period Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` per-1:If present, start SHALL have a lower value than end `start.hasValue().not() or end.hasValue().not() or (start <= end)` Mappings rim:n/a v2:DR rim:IVL<TS>[lowClosed="true" and highClosed="true"] or URG<TS>[lowClosed="true" and highClosed="true"] v2:CX.7 + CX.8 rim:Role.effectiveTime or implied by context servd:./StartDate and ./EndDate
assigner	Σ I	0..1	Reference(UK Core Organization)	There are no (further) constraints on this element Element Id MessageHeader.responsible.identifier.assigner Short description Organization that issued id (may be just text) Definition Organization that issued/manages the identifier. Comments The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization. Data Type Reference(UK Core Organization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:CX.4 / (CX.4,CX.9,CX.10) rim:II.assigningAuthorityName but note that this is an improper use by the definition of the field. Also Role.scoper servd:./IdentifierIssuingAuthority
display	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.responsible.display Short description Text alternative for the resource Definition Plain text narrative that identifies the resource in addition to the resource reference. Comments This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
reason	Σ	0..1	CodeableConceptBinding	Element Id MessageHeader.reason Short description Cause of event Definition `reason` can be used to subdivide `eventCoding`. In the example below, `cancel` is used to indicate the specific reason for the event `prescription-order-update`. The physical cancellation would be the `status=cancelled` in the `MedicationRequest` reason, the reason is a hint. `"reason": { "coding": [ { "system": "https://fhir.nhs.uk/CodeSystem/message-reason-prescription", "code": "cancel", "display": "Cancel" } ] }` Requirements Need to be able to track why resources are being changed and report in the audit log/history of the resource. May affect authorization. Comments Not all terminology uses fit this general pattern. In some cases, models should not use CodeableConcept and use Coding directly and provide their own structure for managing text, codings, translations and the relationship between elements and pre- and post-coordination. Data Type CodeableConcept Binding Reason for event occurrence. MessageReasonCodes (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD w5:FiveWs.why[x] v2:EVN.4 / ORC.16 / OBR-31-reason for study / BPO-13-BP indication for use / RXO-20-indication / RXE-27-give indication / RXD-21-indication / RXG-22-indication / RXA-19-indication rim:unique(./controlAct[classCode="CACT" and classCode="EVN" and isNormalAct()]/reasonCode[isNormalDatatype()])
coding	Σ	0..*	Coding	There are no (further) constraints on this element Element Id MessageHeader.reason.coding Short description Code defined by a terminology system Definition A reference to a code defined by a terminology system. Requirements Allows for alternative encodings within a code system, and translations to other code systems. Comments Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true. Data Type Coding Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE subset one of the sets of component 1-3 or 4-6 rim:CV orim:fhir:Coding rdfs:subClassOf dt:CDCoding v2:CE.1-8, CE.10-22 rim:union(., ./translation) orim:fhir:CodeableConcept.coding rdfs:subPropertyOf dt:CD.coding
system	Σ	1..1	uri	There are no (further) constraints on this element Element Id MessageHeader.reason.coding.system Short description Identity of the terminology system Definition The identification of the code system that defines the meaning of the symbol in the code. Requirements Need to be unambiguous about the source of the definition of the symbol. Comments The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should reference to some definition that establishes the system clearly and unambiguously. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE.3 rim:./codeSystem orim:*fhir:Coding.system rdfs:subPropertyOf dt:CDCoding.codeSystem
version	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.reason.coding.version Short description Version of the system - if relevant Definition The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured, and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged. Comments Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE.7 rim:./codeSystemVersion orim:*fhir:Coding.version rdfs:subPropertyOf dt:CDCoding.codeSystemVersion
code	Σ	1..1	code	There are no (further) constraints on this element Element Id MessageHeader.reason.coding.code Short description Symbol in syntax defined by the system Definition A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination). Requirements Need to refer to a particular code in the system. Comments Note that FHIR strings SHALL NOT exceed 1MB in size Data Type code Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE.1 rim:./code orim:*fhir:Coding.code rdfs:subPropertyOf dt:CDCoding.code
display	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.reason.coding.display Short description Representation defined by the system Definition A representation of the meaning of the code in the system, following the rules of the system. Requirements Need to be able to carry a human-readable meaning of the code for readers that do not know the system. Comments Note that FHIR strings SHALL NOT exceed 1MB in size Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE.2 - but note this is not well followed rim:CV.displayName orim:*fhir:Coding.display rdfs:subPropertyOf dt:CDCoding.displayName
userSelected	Σ	0..1	boolean	There are no (further) constraints on this element Element Id MessageHeader.reason.coding.userSelected Short description If this coding was chosen directly by the user Definition Indicates that this coding was chosen by a user directly - e.g. off a pick list of available items (codes or displays). Requirements This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing. Comments Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely. Data Type boolean Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:Sometimes implied by being first rim:CD.codingRationale orim:fhir:Coding.userSelected fhir:mapsTo dt:CDCoding.codingRationale. fhir:Coding.userSelected fhir:hasMap fhir:Coding.userSelected.map. fhir:Coding.userSelected.map a fhir:Map; fhir:target dt:CDCoding.codingRationale. fhir:Coding.userSelected\#true a [ fhir:source "true"; fhir:target dt:CDCoding.codingRationale\#O ]
text	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.reason.text Short description Plain text representation of the concept Definition A human language representation of the concept as seen/selected/uttered by the user who entered the data and/or which represents the intended meaning of the user. Requirements The codes from the terminologies do not always capture the correct meaning with all the nuances of the human using them, or sometimes there is no appropriate code at all. In these cases, the text is used to capture the full meaning of the source. Comments Very often the text is the same as a displayName of one of the codings. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE.9. But note many systems use CE.2 for this rim:./originalText[mediaType/code="text/plain"]/data orim:fhir:CodeableConcept.text rdfs:subPropertyOf dt:CD.originalText
response	Σ	0..1	BackboneElement	Element Id MessageHeader.response Short description If this is a reply to prior message Definition If the message is a response to a previous message, the `response.identifier` MUST match the previous request messages `Bundle.identifier` Correlation-ID. `"response": { "identifier": "ad945a29-85f8-439a-b590-6789719adc16", "code": "ok" }` Data Type BackboneElement Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:MSA rim:./conveyedAcknowledgement
identifier	Σ	1..1	id	There are no (further) constraints on this element Element Id MessageHeader.response.identifier Short description Id of original message Definition The MessageHeader.id of the message to which this message is a response. Requirements Allows receiver to know what message is being responded to. Comments RFC 4122 Data Type id Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:MSA-2 rim:./acknowledges.id[isNormalDatatype()]
code	Σ	1..1	codeBinding	There are no (further) constraints on this element Element Id MessageHeader.response.code Short description ok \| transient-error \| fatal-error Definition Code that identifies the type of response to the message - whether it was successful or not, and whether it should be resent or not. Requirements Allows the sender of the acknowledge message to know if the request was successful or if action is needed. Comments This is a generic response to the request message. Specific data for the response will be found in MessageHeader.focus. Data Type code Binding The kind of response to a message. ResponseType (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:MSA-1 rim:./typeCode[isNormalDatatype()]
details	Σ I	0..1	Reference(UK Core OperationOutcome)	There are no (further) constraints on this element Element Id MessageHeader.response.details Short description Specific list of hints/warnings/errors Definition Full details of any issues found in the message. Requirements Allows the sender of the message to determine what the specific issues are. Comments This SHALL be contained in the bundle. If any of the issues are errors, the response code SHALL be an error. Data Type Reference(UK Core OperationOutcome) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:ERR rim:AcknowledgementDetail or Observation[classCode="ALRT" and moodCode="EVN"]
reference	Σ I	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.response.details.reference Short description Literal reference, Relative, internal or absolute URL Definition A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources. Comments Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
type	Σ	0..1	uriBinding	There are no (further) constraints on this element Element Id MessageHeader.response.details.type Short description Type the reference refers to (e.g. "Patient") Definition The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent. The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources). Comments This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified. Data Type uri Binding Aa resource (or, for logical models, the URI of the logical model). ResourceType (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
identifier	Σ	0..1	Identifier	There are no (further) constraints on this element Element Id MessageHeader.response.details.identifier Short description Logical reference, when literal reference is not known Definition An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference. Comments When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation\|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any). Data Type Identifier Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CX / EI (occasionally, more often EI maps to a resource id or a URL) rim:II - The Identifier class is a little looser than the v3 type II because it allows URIs as well as registered OIDs or GUIDs. Also maps to Role[classCode=IDENT] servd:Identifier rim:.identifier
use	Σ ?!	0..1	codeBinding	There are no (further) constraints on this element Element Id MessageHeader.response.details.identifier.use Short description usual \| official \| temp \| secondary \| old (If known) Definition The purpose of this identifier. Requirements Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers. Comments Applications can assume that an identifier is permanent unless it explicitly says that it is temporary. Data Type code Binding Identifies the purpose for this identifier, if known . IdentifierUse (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:N/A rim:Role.code or implied by context
type	Σ	0..1	CodeableConceptBinding	There are no (further) constraints on this element Element Id MessageHeader.response.details.identifier.type Short description Description of identifier Definition A coded type for the identifier that can be used to determine which identifier to use for a specific purpose. Requirements Allows users to make use of identifiers when the identifier system is not known. Comments This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type. Data Type CodeableConcept Binding A coded type for an identifier that can be used to determine which identifier to use for a specific purpose. Identifier Type Codes (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD v2:CX.5 rim:Role.code or implied by context
system	Σ	0..1	uri	There are no (further) constraints on this element Element Id MessageHeader.response.details.identifier.system Short description The namespace for the identifier value Definition Establishes the namespace for the value - that is, a URL that describes a set values that are unique. Requirements There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers. Comments Identifier.system is always case sensitive. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General http://www.acme.com/identifiers/patient Mappings rim:n/a v2:CX.4 / EI-2-4 rim:II.root or Role.id.root servd:./IdentifierType
value	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.response.details.identifier.value Short description The value that is unique Definition The portion of the identifier typically relevant to the user and which is unique within the context of the system. Comments If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General 123456 Mappings rim:n/a v2:CX.1 / EI.1 rim:II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root) servd:./Value
period	Σ I	0..1	Period	There are no (further) constraints on this element Element Id MessageHeader.response.details.identifier.period Short description Time period when id is/was valid for use Definition Time period during which identifier is/was valid for use. Comments A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). Period is not used for a duration (a measure of elapsed time). See Duration. Data Type Period Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` per-1:If present, start SHALL have a lower value than end `start.hasValue().not() or end.hasValue().not() or (start <= end)` Mappings rim:n/a v2:DR rim:IVL<TS>[lowClosed="true" and highClosed="true"] or URG<TS>[lowClosed="true" and highClosed="true"] v2:CX.7 + CX.8 rim:Role.effectiveTime or implied by context servd:./StartDate and ./EndDate
assigner	Σ I	0..1	Reference(UK Core Organization)	There are no (further) constraints on this element Element Id MessageHeader.response.details.identifier.assigner Short description Organization that issued id (may be just text) Definition Organization that issued/manages the identifier. Comments The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization. Data Type Reference(UK Core Organization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:CX.4 / (CX.4,CX.9,CX.10) rim:II.assigningAuthorityName but note that this is an improper use by the definition of the field. Also Role.scoper servd:./IdentifierIssuingAuthority
display	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.response.details.display Short description Text alternative for the resource Definition Plain text narrative that identifies the resource in addition to the resource reference. Comments This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
focus	Σ I	1..*	Reference(Resource)	Element Id MessageHeader.focus Short description The actual content of the message Definition The focus element of the MessageHeader specifies the content of the message. The MessageHeader is followed by other resources depending on the type of request. For example, a request to book an appointment may contain the Patient to book the appointment for, the Practitioner to book the appointment with and the actual Appointment that is requested. The focus section SHOULD match the focus section of the corresponding `MessageDefinition` MessageDefinition.focus extract `"focus": [ { "code": "MedicationRequest", "profile": "https://fhir.nhs.uk/StructureDefinition/NHSDigital-MedicationRequest", "min": 1, "max": "4" }, { "code": "Patient", "profile": "https://fhir.nhs.uk/StructureDefinition/NHSDigital-Patient", "min": 1, "max": "1" }, { "code": "CommunicationRequest", "profile": "https://fhir.nhs.uk/StructureDefinition/DM-CommunicationRequest", "min": 0, "max": "" } ]` Corresponding MessageHeader.focus* (Note: type is not required and is included for illustration purposes) `"focus": [ { "type": "Patient", "reference": "urn:uuid:78d3c2eb-009e-4ec8-a358-b042954aa9b2" }, { "type": "MedicationRequest", "reference": "urn:uuid:a54219b8-f741-4c47-b662-e4f8dfa49ab6" }, { "type": "CommunicationRequest", "reference": "urn:uuid:28828C55-8FA7-42D7-916F-FCF076E0C10E" } ]` Requirements Every message event is about actual data, a single resource, that is identified in the definition of the event, and perhaps some or all linked resources. Comments The data is defined where the transaction type is defined. The transaction data is always included in the bundle that is the full message. Only the root resource is specified. The resources it references should be contained in the bundle but are not also listed here. Multiple repetitions are allowed to cater for merges and other situations with multiple focal targets. Data Type Reference(Resource) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) rim:unique(./controlAct[classCode="CACT" and classCode="EVN" and isNormalAct()]/participation[typeCode="SUBJ" and isNormalParticipation]/role or ./controlAct[classCode="CACT" and classCode="EVN" and isNormalAct()]/outboundRelationship[typeCode="SBJ" and isNormalActRelatoinship]/target)
reference	Σ I	1..1	string	There are no (further) constraints on this element Element Id MessageHeader.focus.reference Short description Literal reference, Relative, internal or absolute URL Definition A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources. Comments Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
type	Σ	0..1	uriBinding	There are no (further) constraints on this element Element Id MessageHeader.focus.type Short description Type the reference refers to (e.g. "Patient") Definition The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent. The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources). Comments This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified. Data Type uri Binding Aa resource (or, for logical models, the URI of the logical model). ResourceType (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
identifier	Σ	0..1	Identifier	There are no (further) constraints on this element Element Id MessageHeader.focus.identifier Short description Logical reference, when literal reference is not known Definition An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference. Comments When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation\|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any). Data Type Identifier Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CX / EI (occasionally, more often EI maps to a resource id or a URL) rim:II - The Identifier class is a little looser than the v3 type II because it allows URIs as well as registered OIDs or GUIDs. Also maps to Role[classCode=IDENT] servd:Identifier rim:.identifier
use	Σ ?!	0..1	codeBinding	There are no (further) constraints on this element Element Id MessageHeader.focus.identifier.use Short description usual \| official \| temp \| secondary \| old (If known) Definition The purpose of this identifier. Requirements Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers. Comments Applications can assume that an identifier is permanent unless it explicitly says that it is temporary. Data Type code Binding Identifies the purpose for this identifier, if known . IdentifierUse (required) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:N/A rim:Role.code or implied by context
type	Σ	0..1	CodeableConceptBinding	There are no (further) constraints on this element Element Id MessageHeader.focus.identifier.type Short description Description of identifier Definition A coded type for the identifier that can be used to determine which identifier to use for a specific purpose. Requirements Allows users to make use of identifiers when the identifier system is not known. Comments This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type. Data Type CodeableConcept Binding A coded type for an identifier that can be used to determine which identifier to use for a specific purpose. Identifier Type Codes (extensible) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a v2:CE/CNE/CWE rim:CD orim:fhir:CodeableConcept rdfs:subClassOf dt:CD v2:CX.5 rim:Role.code or implied by context
system	Σ	0..1	uri	There are no (further) constraints on this element Element Id MessageHeader.focus.identifier.system Short description The namespace for the identifier value Definition Establishes the namespace for the value - that is, a URL that describes a set values that are unique. Requirements There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers. Comments Identifier.system is always case sensitive. Data Type uri Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General http://www.acme.com/identifiers/patient Mappings rim:n/a v2:CX.4 / EI-2-4 rim:II.root or Role.id.root servd:./IdentifierType
value	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.focus.identifier.value Short description The value that is unique Definition The portion of the identifier typically relevant to the user and which is unique within the context of the system. Comments If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value extension. Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Examples General 123456 Mappings rim:n/a v2:CX.1 / EI.1 rim:II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root) servd:./Value
period	Σ I	0..1	Period	There are no (further) constraints on this element Element Id MessageHeader.focus.identifier.period Short description Time period when id is/was valid for use Definition Time period during which identifier is/was valid for use. Comments A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). Period is not used for a duration (a measure of elapsed time). See Duration. Data Type Period Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` per-1:If present, start SHALL have a lower value than end `start.hasValue().not() or end.hasValue().not() or (start <= end)` Mappings rim:n/a v2:DR rim:IVL<TS>[lowClosed="true" and highClosed="true"] or URG<TS>[lowClosed="true" and highClosed="true"] v2:CX.7 + CX.8 rim:Role.effectiveTime or implied by context servd:./StartDate and ./EndDate
assigner	Σ I	0..1	Reference(UK Core Organization)	There are no (further) constraints on this element Element Id MessageHeader.focus.identifier.assigner Short description Organization that issued id (may be just text) Definition Organization that issued/manages the identifier. Comments The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization. Data Type Reference(UK Core Organization) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` ref-1:SHALL have a contained resource if a local reference is provided `reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))` Mappings rim:n/a rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity) v2:CX.4 / (CX.4,CX.9,CX.10) rim:II.assigningAuthorityName but note that this is an improper use by the definition of the field. Also Role.scoper servd:./IdentifierIssuingAuthority
display	Σ	0..1	string	There are no (further) constraints on this element Element Id MessageHeader.focus.display Short description Text alternative for the resource Definition Plain text narrative that identifies the resource in addition to the resource reference. Comments This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it. Data Type string Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:N/A
definition	Σ	0..1	canonical(MessageDefinition)	There are no (further) constraints on this element Element Id MessageHeader.definition Short description Link to the definition for this message Definition Permanent link to the MessageDefinition for this message. Requirements Allows sender to define the expected contents of the message. Comments see Canonical References Data Type canonical(MessageDefinition) Constraints ele-1:All FHIR elements must have a @value or children `hasValue() or (children().count() > id.count())` Mappings rim:n/a rim:Not directly supported.

key	human	severity	expression
nhsd-11	replacementOf extension is required for update messages	warning	event.code.where(substring($this.length()-6) = 'update').exists().not() or (event.code.where(substring($this.length()-6) = 'update').exists() and extension('https://fhir.nhs.uk/StructureDefinition/Extension-replacementOf').exists())

MessageHeader

Definition

The header for a FHIR Message exchange that is either requesting or responding to an action. The reference(s) that are the subject of the action as well as other information related to the action are typically transmitted in a bundle in which the MessageHeader resource instance is the first resource in the bundle.

Messaging middleware systems are expected to use this MessageHeader resource to route, deliver and handle messages correctly.

This profile is not tied to any specific transport/API requirement or clinical requirement. Intermediaries are not expected to perform detailed routing on clinical content. Some clinical information will be required for routing purposes and this will be held within eventCoding and reason sections as discussed in the Message Event section below. In circumstances where more detailed information is required for routing this MUST be carried in the relevant FHIR Resource in the payload only. For example, document types should be recorded in FHIR DocumentReference.type and health service/specialty type can be recorded in FHIR Encounter.serviceType or DocumentReference.context.practiceSetting.

Systems involved in NHSDigital/UKCore messaging are expected to support this profile only, extensions or derived profiles are permitted but they may only have limited (internal) scope and will not be supported outside of this scope (e.g. externally). This resource SHOULD NOT be profiled to further define the contents of the resources and FHIR MessageDefinition MUST be used instead.

Comment

identifiers and message timings

FHIR messages have two identifiers: the messageIdentifier of the Message (Bundle.identifier) and a messageId (Bundle.id) which is used in each transport channel . The messageId should be unique within a each message channel/stream. Whenever a message is resent, the messageIdentifier of the Bundle remains the same, but the messageId may change. The response message has its own unique messageIdentifier, the messageIdentifier of the request message can be referenced in the MessageHeader.response.identifier element.

The Bundle.identifier, the messageIdentifier, MUST have a UUID value.

Systems may chose to map X-Request-ID header to the Bundle.id, messageId. If both are supplied to a $process-message endpoint it is recommended they hold the same values.

MessageHeader can hold previous and extra messageId's in the ExtensionMessageHeadermessageId

Local Part/Addressing (sender and/or destination.receiver)

When exchanging messages between organisations, local references SHOULD NOT be used for sender and destination.receiver references. Local references can make use of the Extension ExtensionMessageHeaderLocalPart. Messages between Organisations should be directed to the Organisation. The receiving organisation will take responsibility for delivering to the local address. Sending organisations are not expected to be able to deliver to local entities in another organisation/domain/facility.

This concept is similar to email addresses local-part@domain and also HL7 version 2 combination of Sending/Receiving Application | Sending/Receiving Facility in the MSH segment.

In the example below, the destination is a clinic (A99968) which part of NHS Trust (RBA). Note also the destination endpoint is for the NHS Trust, who will route the message as required.

"destination": [
    {
        "endpoint": "https://directory.spineservices.nhs.uk/STU3/Organization/RBA",
        "receiver": {
          "extension": [
              {
                  "url": "https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-LocalPart",
                  "valueReference": {
                        "identifier": {
                        "system": "https://fhir.nhs.uk/Id/ods-organization-code",
                        "value": "A99968"
                    }
                }

              }
          ],
            "identifier": {
                "system": "https://fhir.nhs.uk/Id/ods-organization-code",
                "value": "RBA"
            },
            "display": "TAUNTON AND SOMERSET NHS FOUNDATION TRUST"
        }
    }
],

example - Prescription, Pharmacy known

nominatedPharmacy

In the example below, the prescriber Taunton and Somerset Foundation Trust (RBA), is sending a message to The Simple Pharmacy (VNE51). The destination.receiver and sender are references to these organisations.

This message is to be sent via the Electronic Prescription Service, the http address of EPS is held in destination.endpoint. Replies to this message can only be received by MESH and the source.endpoint is the MESH address of the sending organisation.

"destination": [
    {
        "endpoint": "https://sandbox.api.service.nhs.uk/electronic-prescriptions/$post-message",
        "receiver": {
            "identifier": {
                "system": "https://fhir.nhs.uk/Id/ods-organization-code",
                "value": "VNE51"
            },
            "display": "The Simple Pharmacy"
        }
    }
],
"sender": {
    "identifier": {
        "extension": [
            {
                "url": "https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-LocalPart",
                "valueReference": {
                        "identifier": {
                        "system": "https://fhir.nhs.uk/Id/ods-organization-code",
                        "value": "A99968"
                    }
                }
            }
        ],
        "system": "https://fhir.nhs.uk/Id/ods-organization-code",
        "value": "RBA"
    },
    "display": "TAUNTON AND SOMERSET NHS FOUNDATION TRUST"
},
"source": {
    "endpoint": "https://directory.spineservices.nhs.uk/STU3/Organization/RBA"
}

EPS will now send this message to the pharmacy. This message is collected by the pharmacy using MESH and so the destination.endpoint is now the MESH address of the pharmacy. Replies to this message are sent to EPS and so the source.endpoint is now the http address of the EPS $process-message endpoint.

"destination": [
    {
        "endpoint": "urn:nhs-uk:addressing:ods:VNE51",
        "receiver": {
            "identifier": {
                "system": "https://fhir.nhs.uk/Id/ods-organization-code",
                "value": "VNE51"
            },
            "display": "The Simple Pharmacy"
        }
    }
],
"sender": {
    "extension": [
            {
                "url": "https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-LocalPart",
                "valueReference": {
                        "identifier": {
                        "system": "https://fhir.nhs.uk/Id/ods-organization-code",
                        "value": "A99968"
                    }
                }

            }
        ],
    "identifier": {
        "system": "https://fhir.nhs.uk/Id/ods-organization-code",
        "value": "RBA"
    },
    "display": "TAUNTON AND SOMERSET NHS FOUNDATION TRUST"
},
"source": {
    "endpoint": "https://sandbox.api.service.nhs.uk/electronic-prescriptions/$post-message"
}

example - Prescription, Pharmacy not known

noNominatedPharmacy

In this example the destination is not known and the message is sent to NHS Digital (X26).

"destination": [
    {
        "endpoint": "https://sandbox.api.service.nhs.uk/electronic-prescriptions/$post-message",
        "receiver": {
    







In addition, a FHIR Message Bundle has two important timestamps:

The time of sending the message is captured in the timestamp element
The last time the message was updated (e.g. by storing or modification) is captured in the meta.lastUpdated element.

```json
{
    "resourceType": "Bundle",
    "id": "884cfa4f-7a56-4be5-9592-783ef4f3992a",
    "meta": {
        "lastUpdated": "2020-11-02T01:43:30+00:00"
      },
    "identifier": {
        "system": "https://tools.ietf.org/html/rfc4122",
        "value": "ad945a29-85f8-439a-b590-6789719adc16"
    },
    "type": "message",
    "timestamp": "2020-11-02T01:43:30+00:00",
    "entry": [
        {
            "fullUrl": "urn:uuid:311316d3-1de0-4f7c-8109-c950ead1c717",
            "resource": {
                "resourceType": "MessageHeader",
                "extension": [
                    {
                        "url": "https://fhir.nhs.uk/StructureDefinition/Extension-Spine-MessageHeader-messageId",
                        "valueIdentifier": {
                            "system": "https://fhir.nhs.uk/Id/prescription-order-number",
                            "value": "DC2C66-A1B2C3-23407B"
                        }
                    }
                ]

From (source and sender) and To (destination)

The From is contained in both the sender and source elements and the To is contained in the destination array. One source, sender and at least one destination MUST be present.

Messages may be sent over multiple transmission legs (i.e. the first leg uses http and the second MESH). The contents of elements SHOULD reflect the current leg only.

destination.endpoint
source.endpoint
MessageHeader.extension(messageId)

Endpoints MUST point to valid endpoint uri's on each leg of the messages journey, they may not refer to inaccessible endpoints on other legs. See also the destination section below.

Constraints

nhsd-11 (WARNING) replacementOf extension is required for update messages
extension:replacementOf
event
destination
sender
sender.identifier
source

extension:replacementOf


Element Id	MessageHeader.extension:replacementOf
Cardinality	0..1
Slice Name	replacementOf
type	Extension(ExtensionreplacementOf)

Definition

If the message is an update or replaceOf a previous message, then this extension should reference the replaced FHIR Message (Bundle.identifier).

"extension": [
    {
        "url": "https://fhir.nhs.uk/StructureDefinition/Extension-replacementOf",
        "valueIdentifier": {
            "system": "https://tools.ietf.org/html/rfc4122",
            "value": "334a3195-1f6c-497a-8efe-d272ca9c4e38"
        }
    }
],

event[x]


Element Id	MessageHeader.event[x]
Cardinality	1..1
Terminology Binding	NHSMessageEvents (Required)
type	Coding

Definition

The main message type is held in the mandatory eventCoding section which can be subdivided by the optional reason codes.

Every code MUST have a corresponding MessageDefinition.

For example the event code dispense-notification has a MessageDefinition of https://fhir.nhs.uk/MessageDefinition/pharmacy-dispense. This definition lists the profiles and cardinality of the resources in the message. eventCoding and MessageDefinition define the structure of the message.

"eventCoding": {
  "system": "https://fhir.nhs.uk/CodeSystem/message-event",
  "code": "dispense-notification",
  "display": "Dispense Notification"
}

Requirements

Drives the behaviour associated with this message.

Comment

The time of the event will be found in the focus resource. The time of the message will be found in Bundle.timestamp.

destination


Element Id	MessageHeader.destination
Cardinality	0..*
type	BackboneElement

Definition

Lists all the destinations where message is be delivered to.

The recipient of a message takes the responsibility of delivering to all the destination.endpoints. Similarly the sender MUST NOT include destination's the recipient can not deliver to, these destinations MUST be removed from the message. Additional rules for endpoint can be found in the source section below.

Requirements

Indicates where message is to be sent for routing purposes. Allows verification of "am I the intended recipient".

"destination": [
                    {
                        "endpoint": "urn:nhs-uk:addressing:mesh:Y90638OT002",
                        "receiver": {
                            "identifier": {
                                "system": "https://fhir.nhs.uk/Id/ods-organization-code",
                                "value": "Y9063"
                            }
                        }
                    }
                ]

Comment

There SHOULD be at least one destination, but in some circumstances, the source system is unaware of any particular destination system.

sender


Element Id	MessageHeader.sender
Cardinality	0..1
type	Reference(NHSDigitalPractitionerRole NHSDigitalPractitioner NHSDigitalOrganization)

Definition

The current requirement in NHS Digital API's is to rely on the Access Tokens and Audit (JWT) for sender details.

For use outside of NHS Digital it is recommended this is populated with either the Organisation ODS code or the Practitioner's professional code.

"sender": {
    "identifier": {
        "system": "https://fhir.nhs.uk/Id/ods-organization-code",
        "value": "VNE51"
   }
}

Requirements

Allows routing beyond just the application level.

Comment

Use case is for where a (trusted) sending system is responsible for multiple organisations, and therefore cannot differentiate based on source endpoint / authentication alone.

sender.identifier


Element Id	MessageHeader.sender.identifier
Cardinality	1..1
type	Identifier

Definition

An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference.

Comment

When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy. When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it. Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any).

source


Element Id	MessageHeader.source
Cardinality	1..1
type	BackboneElement

Definition

source.endpoint is required and MUST indicate the address where replies are to be sent.

For responses to be received via http this will be the address of the $process-message endpoint. E.g.

https://fhir.hospitaltrust.nhs.uk/$process-message

For MESH this will follow ITK2.2 MESH Transport Requirements for ITK Routing. E.g. the MESH Endpoint for Organisation B80310

 "source": {
                    "endpoint": "urn:nhs-uk:addressing:mesh:Y90638OT001"
                }

Requirements

Allows replies, supports audit.