<StructureDefinition xmlns="http://hl7.org/fhir">
  <id value="iso21090-nullFlavor" />
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-wg">
    <valueCode value="fhir" />
  </extension>
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm">
    <valueInteger value="1" />
  </extension>
  <url value="http://hl7.org/fhir/StructureDefinition/iso21090-nullFlavor" />
  <name value="nullFlavor" />
  <status value="draft" />
  <publisher value="Health Level Seven International (Modeling and Methodology)" />
  <contact>
    <telecom>
      <system value="url" />
      <value value="http://www.hl7.org/Special/committees/mnm" />
    </telecom>
  </contact>
  <description value="If the value is not a proper value, indicates the reason." />
  <fhirVersion value="3.0.0" />
  <mapping>
    <identity value="v2" />
    <uri value="http://hl7.org/v2" />
    <name value="HL7 v2 Mapping" />
  </mapping>
  <mapping>
    <identity value="rim" />
    <uri value="http://hl7.org/v3" />
    <name value="RIM Mapping" />
  </mapping>
  <kind value="complex-type" />
  <abstract value="false" />
  <contextType value="datatype" />
  <context value="Any" />
  <type value="Extension" />
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/Extension" />
  <derivation value="constraint" />
  <differential>
    <element id="Extension">
      <path value="Extension" />
      <short value="NI | OTH | NINF | PINF | UNK | ASKU | NAV | NASK | TRC | MSK | NA | QS" />
      <definition value="If the value is not a proper value, indicates the reason." />
      <comment value="Considerable care must be used when using nullFlavor in this context of FHIR - more than any other concept, this is tied to the way v3 works, and FHIR is quite different. For instance, there is no notion of a &quot;proper value&quot; as opposed to any other value in FHIR. a NullFlavor should be understood to mean, &quot;why information is missing&quot;, and the nulFlavors OTH, NINF, PINF, and TRC should not be used." />
      <min value="0" />
      <max value="1" />
      <mapping>
        <identity value="v2" />
        <map value="n/a" />
      </mapping>
      <mapping>
        <identity value="rim" />
        <map value="ANY.nullFlavor" />
      </mapping>
    </element>
    <element id="Extension.extension">
      <path value="Extension.extension" />
      <max value="0" />
    </element>
    <element id="Extension.url">
      <path value="Extension.url" />
      <type>
        <code value="uri" />
      </type>
      <fixedUri value="http://hl7.org/fhir/StructureDefinition/iso21090-nullFlavor" />
    </element>
    <element id="Extension.valueCode">
      <path value="Extension.valueCode" />
      <type>
        <code value="code" />
      </type>
      <binding>
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="NullFlavor" />
        </extension>
        <strength value="required" />
        <description value="A collection of codes specifying why a valid value is not present" />
        <valueSetReference>
          <reference value="http://hl7.org/fhir/ValueSet/v3-NullFlavor" />
        </valueSetReference>
      </binding>
    </element>
  </differential>
</StructureDefinition>