Name Flags Card. Type Description & Constraints doco
. . Extension 0..1 Reason For Current Status
. . . url 1 .. 1 uri "http://fhir.org/guides/argonaut-scheduling/StructureDefinition/extension-status-reason"
. . . valueCodeableConcept 0 .. 1 CodeableConcept Binding: Argonaut_Appointment_Event_Reason_Codes (preferred)

doco Documentation for this format
<status value="active" /> <date value="2017-06-13T00:00:00+10:00" /> <publisher value="Argonaut Project" /> <contact> <telecom> <system value="url" /> <value value="http://argonautwiki.hl7.org" /> </telecom> </contact> <description value="Captures the reason for the current state of the Appointment." /> <jurisdiction> <coding> <system value="urn:iso:std:iso:3166" /> <code value="US" /> <display value="United States of America" /> </coding> </jurisdiction> <fhirVersion value="3.0.1" /> <mapping> <identity value="rim" /> <uri value="http://hl7.org/v3" /> <name value="RIM Mapping" /> </mapping> <kind value="complex-type" /> <abstract value="false" /> <contextType value="resource" /> <context value="Appointment" /> <type value="Extension" /> <baseDefinition value="http://hl7.org/fhir/StructureDefinition/Extension" /> <derivation value="constraint" /> <differential> <element id="Extension"> <path value="Extension" /> <short value="Reason For Current Status" /> <definition value="Captures the reason for the current state of the Appointment." /> <comment value="This is generally only used for "exception" statuses such as `not-done`, `suspended` or `cancelled`. The reason for performing the event at all is captured in the `reason` element, not here." /> <alias value="Suspended Reason" /> <alias value="Cancelled Reason" /> <min value="0" /> <max value="1" /> </element> <element id="Extension.url"> <path value="Extension.url" /> <fixedUri value="http://fhir.org/guides/argonaut-scheduling/StructureDefinition/extension-status-reason" /> </element> <element id="Extension.valueCodeableConcept"> <path value="Extension.valueCodeableConcept" /> <type> <code value="CodeableConcept" /> </type> <binding> <strength value="preferred" /> <description value="The reason for the current state of the Appointment" /> <valueSetReference> <reference value="http://fhir.org/guides/argonaut-scheduling/ValueSet/status-reason" /> </valueSetReference> </binding> </element> </differential> </StructureDefinition>