<StructureDefinition xmlns="http://hl7.org/fhir">
  <id value="elementdefinition-allowedUnits" />
  <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/elementdefinition-allowedUnits" />
  <name value="allowedUnits" />
  <status value="draft" />
  <date value="2015-02-28" />
  <publisher value="Health Level Seven, Inc. - FHIR Core WG" />
  <contact>
    <telecom>
      <system value="url" />
      <value value="http://hl7.org/special/committees/FHIR" />
    </telecom>
  </contact>
  <description value="Identifies the units of measure in which the element should be captured or expressed." />
  <fhirVersion value="3.0.1" />
  <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="ElementDefinition" />
  <type value="Extension" />
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/Extension" />
  <derivation value="constraint" />
  <differential>
    <element id="Extension">
      <path value="Extension" />
      <short value="Units to use for measured value" />
      <definition value="Identifies the units of measure in which the element should be captured or expressed." />
      <comment value="Use a value set if more than one unit of measure is possible.  Value sets will typically be short enough to display in a drop-down selection list." />
      <min value="0" />
      <max value="1" />
      <mapping>
        <identity value="v2" />
        <map value="OM2.2" />
      </mapping>
      <mapping>
        <identity value="rim" />
        <map value="N/A (MIF territory)" />
      </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/elementdefinition-allowedUnits" />
    </element>
    <element id="Extension.value[x]">
      <path value="Extension.value[x]" />
      <min value="1" />
      <type>
        <code value="CodeableConcept" />
      </type>
      <type>
        <code value="Reference" />
        <targetProfile value="http://hl7.org/fhir/StructureDefinition/ValueSet" />
      </type>
      <binding>
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="Units" />
        </extension>
        <strength value="required" />
        <description value="Units of measure allowed for an element" />
        <valueSetReference>
          <reference value="http://hl7.org/fhir/ValueSet/ucum-units" />
        </valueSetReference>
      </binding>
    </element>
  </differential>
</StructureDefinition>