<StructureDefinition xmlns="http://hl7.org/fhir">
  <id value="67329733-af3b-40f1-95f8-a83812dc0a43" />
  <url value="https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-LocalPart" />
  <name value="ExtensionMessageHeaderLocalPart" />
  <status value="draft" />
  <fhirVersion value="4.0.1" />
  <mapping>
    <identity value="rim" />
    <uri value="http://hl7.org/v3" />
    <name value="RIM Mapping" />
  </mapping>
  <kind value="complex-type" />
  <abstract value="false" />
  <context>
    <type value="element" />
    <expression value="MessageHeader.sender" />
  </context>
  <context>
    <type value="element" />
    <expression value="MessageHeader.destination.receiver" />
  </context>
  <type value="Extension" />
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/Extension" />
  <derivation value="constraint" />
  <differential>
    <element id="Extension.url">
      <path value="Extension.url" />
      <fixedUri value="https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-LocalPart" />
    </element>
    <element id="Extension.value[x]">
      <path value="Extension.value[x]" />
      <type>
        <code value="Reference" />
        <targetProfile value="https://fhir.nhs.uk/StructureDefinition/NHSDigital-HealthcareService" />
        <targetProfile value="https://fhir.nhs.uk/StructureDefinition/NHSDigital-PractitionerRole" />
        <targetProfile value="https://fhir.nhs.uk/StructureDefinition/NHSDigital-Practitioner" />
      </type>
    </element>
    <element id="Extension.value[x].identifier.system">
      <path value="Extension.value[x].identifier.system" />
      <min value="1" />
    </element>
    <element id="Extension.value[x].identifier.value">
      <path value="Extension.value[x].identifier.value" />
      <min value="1" />
    </element>
  </differential>
</StructureDefinition>