Extension Library(active)
This extension library contains all the extensions Clinically and Technically Assuranced for use with UK Core. The profiles are found in the Profiles Index. The table below lists all the current extensions and the context of use. The context of use column indicates the profile and /or element where the extension may be applied. The type column indicates whether the extension is an modifierExtension or not. The general rule is extensions can be ignored by receivers*. When a modifierExtension is received it MUST NOT be ignored as it modifies the meaning of the element or elements that contains it. Typically, this means information that qualifies or negates the primary meaning of the element that contains it.
For more information from HL7 about FHIR extensions.
For more information from HL7 about FHIR modifierExtensions.
*There may be specific use cases where this is not the case and the Domain Implementation Guidance associated with the use case should be consulted.
All the extensions have been assured as suitable for inclusion in the UK Core, however all extensions have been assigned a maturity level similar to the maturity levels described in the FHIR standard. This is intended to indicate how stable the extension is deemed to be, this is in addition to the publication status of the profile HL7 FHIR statuses of draft, active, retired and unknown.
| Maturity level | Definition |
|---|---|
| 0 | The Extension has been published on the current build. This Extension has had no formal review and therefore may have quality issues. It is published only to allow the review process to start |
| 1 | The Extension produces no warnings during the build process and has had a formal internal review by the UK Core development team |
| 2 | The Extension has been released for review to the UK FHIR community, any feedback received has been addressed as far as possible |
| 3 | The Extension has been presented for inclusion in the Technical and Clinical Assurance process |
| 4 | The Extension has completed the Technical and Clinical Assurance process and the status has been changed to active |
| 5 | The Extension has been presented for inclusion in the HL7 UK Ballot Process |
| 6 | The Extension has completed the HL7 UK Ballot process and is now deemed to be Normative |
The Extensions are rendered in several formats:
- Snapshot: a fully calculated form of the structure that is not dependent on any other structure
- Differential: this describes only the differences that the Extension makes relative to the structure definition (FHIR resource) they constrain
- Hybrid: a hybrid view of the snapshot and differential views
- Table: a tabular view of the Extension elements
- XML: a rendering of a XML view of the Extension
- JSON: a rendering of a JSON view of the Extension
Further information from HL7 relating to extensibility is available.
Implementers of the UK Core profiles may also create their own Extensions where required, but are encouraged to engage with the UK Core development process to get their extensions adopted into the UK Core for wider use by the UK FHIR Community.
For the current list of UK Core extensions under development refer to HL7 FHIR® UK Core Profile Implementation Guide R4 (Draft) Extension Libruary.