<StructureDefinition xmlns="http://hl7.org/fhir">
  <id value="code" />
  <text>
    <status value="generated" />
    <div xmlns="http://www.w3.org/1999/xhtml">to do</div>
  </text>
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status">
    <valueCode value="normative" />
  </extension>
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-normative-version">
    <valueCode value="4.0.0" />
  </extension>
  <url value="http://hl7.org/fhir/StructureDefinition/code" />
  <version value="4.0.1" />
  <name value="code" />
  <status value="active" />
  <date value="2019-11-01T09:29:23+11:00" />
  <publisher value="HL7 FHIR Standard" />
  <contact>
    <telecom>
      <system value="url" />
      <value value="http://hl7.org/fhir" />
    </telecom>
  </contact>
  <description value="Base StructureDefinition for code type: A string which has at least one character and no leading or trailing whitespace and where there is no whitespace other than single spaces in the contents" />
  <fhirVersion value="4.0.1" />
  <kind value="primitive-type" />
  <abstract value="false" />
  <type value="code" />
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/string" />
  <derivation value="specialization" />
  <snapshot>
    <element id="code">
      <path value="code" />
      <short value="Primitive Type code" />
      <definition value="A string which has at least one character and no leading or trailing whitespace and where there is no whitespace other than single spaces in the contents" />
      <min value="0" />
      <max value="*" />
      <base>
        <path value="code" />
        <min value="0" />
        <max value="*" />
      </base>
      <constraint>
        <key value="ele-1" />
        <severity value="error" />
        <human value="All FHIR elements must have a @value or children" />
        <expression value="hasValue() or (children().count() &gt; id.count())" />
        <xpath value="@value|f:*|h:div" />
        <source value="http://hl7.org/fhir/StructureDefinition/Element" />
      </constraint>
      <isModifier value="false" />
      <isSummary value="false" />
    </element>
    <element id="code.id">
      <path value="code.id" />
      <representation value="xmlAttr" />
      <short value="xml:id (or equivalent in JSON)" />
      <definition value="unique id for the element within a resource (for internal references)" />
      <min value="0" />
      <max value="1" />
      <base>
        <path value="Element.id" />
        <min value="0" />
        <max value="1" />
      </base>
      <type>
        <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
          <valueUrl value="string" />
        </extension>
        <code value="http://hl7.org/fhirpath/System.String" />
      </type>
      <isModifier value="false" />
      <isSummary value="false" />
    </element>
    <element id="code.extension">
      <path value="code.extension" />
      <short value="Additional content defined by implementations" />
      <definition value="May be used to represent additional information that is not part of the basic definition of the resource. To make the use of extensions safe and manageable, there is a strict set of governance  applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension." />
      <comment value="There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions.  The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone." />
      <alias value="extensions" />
      <alias value="user content" />
      <min value="0" />
      <max value="*" />
      <base>
        <path value="Element.extension" />
        <min value="0" />
        <max value="*" />
      </base>
      <type>
        <code value="Extension" />
      </type>
      <constraint>
        <key value="ele-1" />
        <severity value="error" />
        <human value="All FHIR elements must have a @value or children" />
        <expression value="hasValue() or (children().count() &gt; id.count())" />
        <xpath value="@value|f:*|h:div" />
        <source value="http://hl7.org/fhir/StructureDefinition/Element" />
      </constraint>
      <constraint>
        <key value="ext-1" />
        <severity value="error" />
        <human value="Must have either extensions or value[x], not both" />
        <expression value="extension.exists() != value.exists()" />
        <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), 'value')])" />
        <source value="http://hl7.org/fhir/StructureDefinition/Extension" />
      </constraint>
      <isModifier value="false" />
      <isSummary value="false" />
    </element>
    <element id="code.value">
      <path value="code.value" />
      <representation value="xmlAttr" />
      <short value="Primitive value for code" />
      <definition value="Primitive value for code" />
      <min value="0" />
      <max value="1" />
      <base>
        <path value="string.value" />
        <min value="0" />
        <max value="1" />
      </base>
      <type>
        <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
          <valueUrl value="string" />
        </extension>
        <extension url="http://hl7.org/fhir/StructureDefinition/regex">
          <valueString value="[^\s]+(\s[^\s]+)*" />
        </extension>
        <code value="http://hl7.org/fhirpath/System.String" />
      </type>
      <isModifier value="false" />
      <isSummary value="false" />
    </element>
  </snapshot>
  <differential>
    <element id="code">
      <path value="code" />
      <short value="Primitive Type code" />
      <definition value="A string which has at least one character and no leading or trailing whitespace and where there is no whitespace other than single spaces in the contents" />
      <min value="0" />
      <max value="*" />
    </element>
    <element id="code.value">
      <path value="code.value" />
      <representation value="xmlAttr" />
      <short value="Primitive value for code" />
      <definition value="Primitive value for code" />
      <min value="0" />
      <max value="1" />
      <type>
        <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
          <valueUrl value="code" />
        </extension>
        <extension url="http://hl7.org/fhir/StructureDefinition/regex">
          <valueString value="[^\s]+(\s[^\s]+)*" />
        </extension>
        <code value="http://hl7.org/fhirpath/System.String" />
      </type>
    </element>
  </differential>
</StructureDefinition>