<StructureDefinition xmlns="http://hl7.org/fhir">
  <id value="KBV-PR-Base-Identifier-KVK" />
  <url value="https://fhir.kbv.de/StructureDefinition/KBV_PR_Base_Identifier_KVK" />
  <version value="1.3.0" />
  <name value="KBV_PR_Base_Identifier_KVK" />
  <status value="draft" />
  <fhirVersion value="4.0.1" />
  <kind value="complex-type" />
  <abstract value="false" />
  <type value="Identifier" />
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/Identifier" />
  <derivation value="constraint" />
  <differential>
    <element id="Identifier">
      <path value="Identifier" />
      <short value="Identifier KVK" />
      <definition value="Versichertennummer der Krankenversichertenkarte (KVK)" />
    </element>
    <element id="Identifier.type">
      <path value="Identifier.type" />
      <min value="1" />
      <patternCodeableConcept>
        <coding>
          <system value="https://fhir.kbv.de/CodeSystem/KBV_CS_Base_identifier_type" />
          <code value="kvk" />
          <display value="Krankenversichertenkarte" />
        </coding>
      </patternCodeableConcept>
    </element>
    <element id="Identifier.type.coding">
      <path value="Identifier.type.coding" />
      <min value="1" />
      <max value="1" />
    </element>
    <element id="Identifier.type.coding.system">
      <path value="Identifier.type.coding.system" />
      <min value="1" />
    </element>
    <element id="Identifier.type.coding.code">
      <path value="Identifier.type.coding.code" />
      <min value="1" />
    </element>
    <element id="Identifier.system">
      <path value="Identifier.system" />
      <min value="1" />
      <fixedUri value="http://fhir.de/sid/gkv/kvk-versichertennummer" />
    </element>
    <element id="Identifier.value">
      <path value="Identifier.value" />
      <min value="1" />
      <constraint>
        <key value="kvk-1" />
        <severity value="error" />
        <human value="Die Krankenversichertenkartenummer muss numerisch und 6- bis 12-stellig sein." />
        <expression value="matches('^[0-9]{6,12}$')" />
        <source value="https://fhir.kbv.de/StructureDefinition/KBV_PR_Base_Identifier_KVK" />
      </constraint>
    </element>
  </differential>
</StructureDefinition>