HL7 v2+ Specification
0.0.0 - draft

HL7 v2+ Specification, published by HL7 International. This guide is not an authorized publication; it is the continuous build for version 0.0.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/HL7/v2ig/ and changes regularly. See the Directory of published versions

Resource Profile: V2DataTypeDefinition - XML Profile

Page standards status: Informative

XML representation of the v2-primitive-data-type-profile resource profile.

Raw xml | Download


<StructureDefinition xmlns="http://hl7.org/fhir">
  <id value="v2-primitive-data-type-profile"/>
  <text>
    <status value="extensions"/>
    <div xmlns="http://www.w3.org/1999/xhtml"><p class="res-header-id"><b>Generated Narrative: StructureDefinition v2-primitive-data-type-profile</b></p><a name="v2-primitive-data-type-profile"> </a><a name="hcv2-primitive-data-type-profile"> </a><a name="v2-primitive-data-type-profile-en-US"> </a><table border="0" cellpadding="0" cellspacing="0" style="border: 0px #F0F0F0 solid; font-size: 11px; font-family: verdana; vertical-align: top;"><tr style="border: 1px #F0F0F0 solid; font-size: 11px; font-family: verdana; vertical-align: top"><th style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="The logical name of the element">Name</a></th><th style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Information about the use of the element">Flags</a></th><th style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Minimum and Maximum # of times the element can appear in the instance">Card.</a></th><th style="width: 100px" class="hierarchy"><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Reference to the type of the element">Type</a></th><th style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Additional information about the element">Description &amp; Constraints</a><span style="float: right"><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Legend for this format"><img src="data:image/png;base64,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" alt="doco" style="background-color: inherit"/></a></span></th></tr><tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color: white"><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; white-space: nowrap; background-image: url(tbl_bck1.png)" class="hierarchy"><img src="tbl_spacer.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="icon_resource.png" alt="." style="background-color: white; background-color: inherit" title="Resource" class="hierarchy"/> <a href="StructureDefinition-v2-primitive-data-type-profile-definitions.html#StructureDefinition">StructureDefinition</a><a name="StructureDefinition"> </a></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="opacity: 0.5">0</span><span style="opacity: 0.5">..</span><span style="opacity: 0.5">*</span></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a href="http://hl7.org/fhir/R5/structuredefinition.html">StructureDefinition</a></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="opacity: 0.5">Structural Definition</span></td></tr>
<tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color: #F7F7F7"><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; white-space: nowrap; background-image: url(tbl_bck10.png)" class="hierarchy"><img src="tbl_spacer.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="tbl_vjoin.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="icon_element.gif" alt="." style="background-color: #F7F7F7; background-color: inherit" title="Element" class="hierarchy"/> <a href="StructureDefinition-v2-primitive-data-type-profile-definitions.html#StructureDefinition.url">url</a><a name="StructureDefinition.url"> </a></td><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="opacity: 0.5">1</span><span style="opacity: 0.5">..</span><span style="opacity: 0.5">1</span></td><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a style="opacity: 0.5" href="http://hl7.org/fhir/R5/datatypes.html#uri">uri</a></td><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="opacity: 0.5">Canonical identifier for this structure definition, represented as a URI (globally unique)</span><br/><span style="font-weight:bold">Binding: </span><a href="ValueSet-v2-vs-primitive-data-type-urls.html" title="http://hl7.org/v2/ValueSet/v2-vs-primitive-data-type-urls">HL7 v2 Primitive Data Type URLs ValueSet</a> (<a href="http://hl7.org/fhir/R5/terminologies.html#required" title="To be conformant, the concept in this element SHALL be from the specified value set.">required</a>)</td></tr>
<tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color: white"><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; white-space: nowrap; background-image: url(tbl_bck10.png)" class="hierarchy"><img src="tbl_spacer.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="tbl_vjoin.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="icon_element.gif" alt="." style="background-color: white; background-color: inherit" title="Element" class="hierarchy"/> <a href="StructureDefinition-v2-primitive-data-type-profile-definitions.html#StructureDefinition.kind">kind</a><a name="StructureDefinition.kind"> </a></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="opacity: 0.5">1</span><span style="opacity: 0.5">..</span><span style="opacity: 0.5">1</span></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a style="opacity: 0.5" href="http://hl7.org/fhir/R5/datatypes.html#code">code</a></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="opacity: 0.5">primitive-type | complex-type | resource | logical</span><br/><span style="font-weight:bold">Fixed Value: </span><span style="color: darkgreen">primitive-type</span></td></tr>
<tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color: #F7F7F7"><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; white-space: nowrap; background-image: url(tbl_bck10.png)" class="hierarchy"><img src="tbl_spacer.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="tbl_vjoin.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="icon_element.gif" alt="." style="background-color: #F7F7F7; background-color: inherit" title="Element" class="hierarchy"/> <a href="StructureDefinition-v2-primitive-data-type-profile-definitions.html#StructureDefinition.abstract">abstract</a><a name="StructureDefinition.abstract"> </a></td><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="opacity: 0.5">1</span><span style="opacity: 0.5">..</span><span style="opacity: 0.5">1</span></td><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a style="opacity: 0.5" href="http://hl7.org/fhir/R5/datatypes.html#boolean">boolean</a></td><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="opacity: 0.5">Whether the structure is abstract</span><br/><span style="font-weight:bold">Fixed Value: </span><span style="color: darkgreen">false</span></td></tr>
<tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color: white"><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; white-space: nowrap; background-image: url(tbl_bck00.png)" class="hierarchy"><img src="tbl_spacer.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="tbl_vjoin_end.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="icon_element.gif" alt="." style="background-color: white; background-color: inherit" title="Element" class="hierarchy"/> <a href="StructureDefinition-v2-primitive-data-type-profile-definitions.html#StructureDefinition.derivation">derivation</a><a name="StructureDefinition.derivation"> </a></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="opacity: 0.5">0</span><span style="opacity: 0.5">..</span><span style="opacity: 0.5">1</span></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a style="opacity: 0.5" href="http://hl7.org/fhir/R5/datatypes.html#code">code</a></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="opacity: 0.5">specialization | constraint - How relates to base definition</span><br/><span style="font-weight:bold">Fixed Value: </span><span style="color: darkgreen">constraint</span></td></tr>
<tr><td colspan="5" class="hierarchy"><br/><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Legend for this format"><img src="data:image/png;base64,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" alt="doco" style="background-color: inherit"/> Documentation for this format</a></td></tr></table></div>
  </text>
  <extension
             url="http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status">
    <valueCode value="informative">
      <extension
                 url="http://hl7.org/fhir/StructureDefinition/structuredefinition-conformance-derivedFrom">
        <valueCanonical
                        value="http://somewhere.org/fhir/uv/v2plus/ImplementationGuide/hl7.other.uv.v2plus"/>
      </extension>
    </valueCode>
  </extension>
  <url value="http://hl7.org/v2/StructureDefinition/Primitive-Profile"/>
  <version value="0.0.0"/>
  <name value="V2DataTypeDefinition"/>
  <title value="HL7 v2 Data Type Definition"/>
  <status value="active"/>
  <date value="2024-11-08T13:58:48+00:00"/>
  <publisher value="HL7 International"/>
  <contact>
    <telecom>
      <system value="url"/>
      <value value="http://hl7.org/Special/committees/v2mgmt"/>
    </telecom>
  </contact>
  <description
               value="Rules that are true for all primitive type definitions"/>
  <fhirVersion value="5.0.0"/>
  <mapping>
    <identity value="w5"/>
    <uri value="http://hl7.org/fhir/fivews"/>
    <name value="FiveWs Pattern Mapping"/>
  </mapping>
  <mapping>
    <identity value="rim"/>
    <uri value="http://hl7.org/v3"/>
    <name value="RIM Mapping"/>
  </mapping>
  <mapping>
    <identity value="iso11179"/>
    <uri value="http://metadata-standards.org/11179/"/>
    <name value="ISO 11179"/>
  </mapping>
  <mapping>
    <identity value="objimpl"/>
    <uri value="http://hl7.org/fhir/object-implementation"/>
    <name value="Object Implementation Information"/>
  </mapping>
  <kind value="resource"/>
  <abstract value="false"/>
  <type value="StructureDefinition"/>
  <baseDefinition
                  value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
  <derivation value="constraint"/>
  <snapshot>
    <element id="StructureDefinition">
      <path value="StructureDefinition"/>
      <short value="Structural Definition"/>
      <definition
                  value="A definition of a FHIR structure. This resource is used to describe the underlying resources, data types defined in FHIR, and also for describing extensions and constraints on resources and data types."/>
      <alias value="Template"/>
      <alias value="Profile"/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="StructureDefinition"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <constraint>
        <key value="cnl-0"/>
        <severity value="warning"/>
        <human
               value="Name should be usable as an identifier for the module by machine processing applications such as code generation"/>
        <expression
                    value="name.exists() implies name.matches('^[A-Z]([A-Za-z0-9_]){1,254}$')"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-1"/>
        <severity value="error"/>
        <human
               value="Element paths must be unique unless the structure is a constraint"/>
        <expression
                    value="derivation = 'constraint' or snapshot.element.select(path).isDistinct()"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-4"/>
        <requirements value="Ensure that the base types are abstract"/>
        <severity value="error"/>
        <human
               value="If the structure is not abstract, then there SHALL be a baseDefinition"/>
        <expression value="abstract = true or baseDefinition.exists()"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-5"/>
        <severity value="error"/>
        <human
               value="If the structure defines an extension then the structure must have context information"/>
        <expression
                    value="type != 'Extension' or derivation = 'specialization' or (context.exists())"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-6"/>
        <severity value="error"/>
        <human
               value="A structure must have either a differential, or a snapshot (or both)"/>
        <expression value="snapshot.exists() or differential.exists()"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-11"/>
        <requirements
                      value="Ensure that the type is not inconsistent with the other information in the structure"/>
        <severity value="error"/>
        <human
               value="If there's a type, its content must match the path name in the first element of a snapshot"/>
        <expression
                    value="kind != 'logical' implies snapshot.empty() or snapshot.element.first().path = type"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-14"/>
        <requirements value="elements have id"/>
        <severity value="error"/>
        <human value="All element definitions must have an id"/>
        <expression
                    value="snapshot.element.all(id.exists()) and differential.element.all(id.exists())"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-15"/>
        <requirements value="No Type on the root element (snapshot)"/>
        <severity value="error"/>
        <human
               value="The first element in a snapshot has no type unless model is a logical model."/>
        <expression
                    value="kind!='logical'  implies snapshot.element.first().type.empty()"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-15a"/>
        <requirements value="No Type on the root element (differential)"/>
        <severity value="error"/>
        <human
               value="If the first element in a differential has no &quot;.&quot; in the path and it's not a logical model, it has no type"/>
        <expression
                    value="(kind!='logical'  and differential.element.first().path.contains('.').not()) implies differential.element.first().type.empty()"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-9"/>
        <requirements
                      value="Because these 3 fields seem to be have overlapping meaning with the ones in the root of StructureDefinition"/>
        <severity value="error"/>
        <human
               value="In any snapshot or differential, no label, code or requirements on an element without a &quot;.&quot; in the path (e.g. the first element)"/>
        <expression
                    value="children().element.where(path.contains('.').not()).label.empty() and children().element.where(path.contains('.').not()).code.empty() and children().element.where(path.contains('.').not()).requirements.empty()"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-16"/>
        <requirements value="element ids need to be unique"/>
        <severity value="error"/>
        <human
               value="All element definitions must have unique ids (snapshot)"/>
        <expression
                    value="snapshot.element.all(id.exists()) and snapshot.element.id.trace('ids').isDistinct()"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-17"/>
        <requirements value="element ids need to be unique"/>
        <severity value="error"/>
        <human value="All element definitions must have unique ids (diff)"/>
        <expression
                    value="differential.element.all(id.exists()) and differential.element.id.trace('ids').isDistinct()"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-18"/>
        <requirements value="contextInvariant"/>
        <severity value="error"/>
        <human value="Context Invariants can only be used for extensions"/>
        <expression
                    value="contextInvariant.exists() implies type = 'Extension'"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-19"/>
        <requirements value="custom types only in logical models"/>
        <severity value="error"/>
        <human value="FHIR Specification models only use FHIR defined types"/>
        <expression
                    value="url.startsWith('http://hl7.org/fhir/StructureDefinition') implies (differential | snapshot).element.type.code.all(matches('^[a-zA-Z0-9]+$') or matches('^http:\\/\\/hl7\\.org\\/fhirpath\\/System\\.[A-Z][A-Za-z]+$'))"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-21"/>
        <requirements value="no default values on data types or resources"/>
        <severity value="error"/>
        <human
               value="Default values can only be specified on specializations"/>
        <expression
                    value="differential.element.defaultValue.exists() implies (derivation = 'specialization')"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-22"/>
        <requirements value="no default values on data types or resources"/>
        <severity value="error"/>
        <human value="FHIR Specification models never have default values"/>
        <expression
                    value="url.startsWith('http://hl7.org/fhir/StructureDefinition') implies (snapshot.element.defaultValue.empty() and differential.element.defaultValue.empty())"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-23"/>
        <requirements value="no sliceName on root"/>
        <severity value="error"/>
        <human value="No slice name on root"/>
        <expression
                    value="(snapshot | differential).element.all(path.contains('.').not() implies sliceName.empty())"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-27"/>
        <severity value="error"/>
        <human
               value="If there's a base definition, there must be a derivation "/>
        <expression
                    value="baseDefinition.exists() implies derivation.exists()"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-29"/>
        <severity value="warning"/>
        <human
               value="Elements in Resources must have a min cardinality or 0 or 1 and a max cardinality of 1 or *"/>
        <expression
                    value="((kind in 'resource' | 'complex-type') and (derivation = 'specialization')) implies differential.element.where((min != 0 and min != 1) or (max != '1' and max != '*')).empty()"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="w5"/>
        <map value="conformance.behavior,conformance.content"/>
      </mapping>
      <mapping>
        <identity value="rim"/>
        <map value="n/a"/>
      </mapping>
    </element>
    <element id="StructureDefinition.id">
      <path value="StructureDefinition.id"/>
      <short value="Logical id of this artifact"/>
      <definition
                  value="The logical id of the resource, as used in the URL for the resource. Once assigned, this value never changes."/>
      <comment
               value="Within the context of the FHIR RESTful interactions, the resource has an id except for cases like the create and conditional update. Otherwise, the use of the resouce id depends on the given use case."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="Resource.id"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
          <valueUrl value="id"/>
        </extension>
        <code value="http://hl7.org/fhirpath/System.String"/>
      </type>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="StructureDefinition.meta">
      <path value="StructureDefinition.meta"/>
      <short value="Metadata about the resource"/>
      <definition
                  value="The metadata about the resource. This is content that is maintained by the infrastructure. Changes to the content might not always be associated with version changes to the resource."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="Resource.meta"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="Meta"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="StructureDefinition.implicitRules">
      <path value="StructureDefinition.implicitRules"/>
      <short value="A set of rules under which this content was created"/>
      <definition
                  value="A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc."/>
      <comment
               value="Asserting this rule set restricts the content to be only understood by a limited set of trading partners. This inherently limits the usefulness of the data in the long term. However, the existing health eco-system is highly fractured, and not yet ready to define, collect, and exchange data in a generally computable sense. Wherever possible, implementers and/or specification writers should avoid using this element. Often, when used, the URL is a reference to an implementation guide that defines these special rules as part of its narrative along with other profiles, value sets, etc."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="Resource.implicitRules"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="uri"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="true"/>
      <isModifierReason
                        value="This element is labeled as a modifier because the implicit rules may provide additional knowledge about the resource that modifies its meaning or interpretation"/>
      <isSummary value="true"/>
    </element>
    <element id="StructureDefinition.language">
      <path value="StructureDefinition.language"/>
      <short value="Language of the resource content"/>
      <definition
                  value="The base language in which the resource is written."/>
      <comment
               value="Language is provided to support indexing and accessibility (typically, services such as text to speech use the language tag). The html language tag in the narrative applies  to the narrative. The language tag on the resource may be used to specify the language of other presentations generated from the data in the resource. Not all the content has to be in the base language. The Resource.language should not be assumed to apply to the narrative automatically. If a language is specified, it should it also be specified on the div element in the html (see rules in HTML5 for information about the relationship between xml:lang and the html lang attribute)."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="Resource.language"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="code"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <binding>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="Language"/>
        </extension>
        <strength value="required"/>
        <description value="IETF language tag for a human language"/>
        <valueSet value="http://hl7.org/fhir/ValueSet/all-languages|5.0.0"/>
        <additional>
          <purpose value="starter"/>
          <valueSet value="http://hl7.org/fhir/ValueSet/languages"/>
        </additional>
      </binding>
    </element>
    <element id="StructureDefinition.text">
      <path value="StructureDefinition.text"/>
      <short value="Text summary of the resource, for human interpretation"/>
      <definition
                  value="A human-readable narrative that contains a summary of the resource and can be used to represent the content of the resource to a human. The narrative need not encode all the structured data, but is required to contain sufficient detail to make it &quot;clinically safe&quot; for a human to just read the narrative. Resource definitions may define what content should be represented in the narrative to ensure clinical safety."/>
      <comment
               value="Contained resources do not have a narrative. Resources that are not contained SHOULD have a narrative. In some cases, a resource may only have text with little or no additional discrete data (as long as all minOccurs=1 elements are satisfied).  This may be necessary for data from legacy systems where information is captured as a &quot;text blob&quot; or where text is additionally entered raw or narrated and encoded information is added later."/>
      <alias value="narrative"/>
      <alias value="html"/>
      <alias value="xhtml"/>
      <alias value="display"/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="DomainResource.text"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="Narrative"/>
      </type>
      <condition value="dom-6"/>
      <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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="Act.text?"/>
      </mapping>
    </element>
    <element id="StructureDefinition.contained">
      <path value="StructureDefinition.contained"/>
      <short value="Contained, inline Resources"/>
      <definition
                  value="These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, nor can they have their own independent transaction scope. This is allowed to be a Parameters resource if and only if it is referenced by a resource that provides context/meaning."/>
      <comment
               value="This should never be done when the content can be identified properly, as once identification is lost, it is extremely difficult (and context dependent) to restore it again. Contained resources may have profiles and tags in their meta elements, but SHALL NOT have security labels."/>
      <alias value="inline resources"/>
      <alias value="anonymous resources"/>
      <alias value="contained resources"/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="DomainResource.contained"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="Resource"/>
      </type>
      <condition value="dom-2"/>
      <condition value="dom-4"/>
      <condition value="dom-3"/>
      <condition value="dom-5"/>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="N/A"/>
      </mapping>
    </element>
    <element id="StructureDefinition.extension">
      <path value="StructureDefinition.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 managable, 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="DomainResource.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())"/>
        <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()"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="N/A"/>
      </mapping>
    </element>
    <element id="StructureDefinition.modifierExtension">
      <path value="StructureDefinition.modifierExtension"/>
      <short value="Extensions that cannot be ignored"/>
      <definition
                  value="May be used to represent additional information that is not part of the basic definition of the resource and that modifies the understanding of the element that contains it and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself)."/>
      <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."/>
      <requirements
                    value="Modifier extensions allow for extensions that *cannot* be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored.  This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the [definition of modifier extensions](http://hl7.org/fhir/R5/extensibility.html#modifierExtension)."/>
      <alias value="extensions"/>
      <alias value="user content"/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="DomainResource.modifierExtension"/>
        <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())"/>
        <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()"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="true"/>
      <isModifierReason
                        value="Modifier extensions are expected to modify the meaning or interpretation of the resource that contains them"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="rim"/>
        <map value="N/A"/>
      </mapping>
    </element>
    <element id="StructureDefinition.url">
      <path value="StructureDefinition.url"/>
      <short
             value="Canonical identifier for this structure definition, represented as a URI (globally unique)"/>
      <definition
                  value="An absolute URI that is used to identify this structure definition when it is referenced in a specification, model, design or an instance; also called its canonical identifier. This SHOULD be globally unique and SHOULD be a literal address at which an authoritative instance of this structure definition is (or will be) published. This URL can be the target of a canonical reference. It SHALL remain the same when the structure definition is stored on different servers."/>
      <comment
               value="Can be a urn:uuid: or a urn:oid: but real http: addresses are preferred.  Multiple instances may share the same URL if they have a distinct version.

The determination of when to create a new version of a resource (same url, new version) vs. defining a new artifact is up to the author.  Considerations for making this decision are found in [Technical and Business Versions](http://hl7.org/fhir/R5/resource.html#versions). 

In some cases, the resource can no longer be found at the stated url, but the url itself cannot change. Implementations can use the [meta.source](http://hl7.org/fhir/R5/resource.html#meta) element to indicate where the current master source of the resource can be found."/>
      <requirements
                    value="Allows the structure definition to be referenced by a single globally unique identifier."/>
      <alias value="url"/>
      <alias value="authoritative-url"/>
      <alias value="destination"/>
      <alias value="identity"/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.url"/>
        <min value="1"/>
        <max value="1"/>
      </base>
      <type>
        <code value="uri"/>
      </type>
      <condition value="sdf-19"/>
      <condition value="sdf-22"/>
      <constraint>
        <key value="cnl-1"/>
        <severity value="warning"/>
        <human
               value="URL should not contain | or # - these characters make processing canonical references problematic"/>
        <expression value="exists() implies matches('^[^|# ]+$')"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <binding>
        <strength value="required"/>
        <valueSet
                  value="http://hl7.org/v2/ValueSet/v2-vs-primitive-data-type-urls"/>
      </binding>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.identifier"/>
      </mapping>
    </element>
    <element id="StructureDefinition.identifier">
      <path value="StructureDefinition.identifier"/>
      <short value="Additional identifier for the structure definition"/>
      <definition
                  value="A formal identifier that is used to identify this structure definition when it is represented in other formats, or referenced in a specification, model, design or an instance."/>
      <comment
               value="Typically, this is used for identifiers that can go in an HL7 V3 II (instance identifier) data type, and can then identify this structure definition outside of FHIR, where it is not possible to use the logical URI."/>
      <requirements
                    value="Allows externally provided and/or usable business identifiers to be easily associated with the module."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="StructureDefinition.identifier"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="Identifier"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.identifier"/>
      </mapping>
      <mapping>
        <identity value="iso11179"/>
        <map value="Identifier part"/>
      </mapping>
      <mapping>
        <identity value="objimpl"/>
        <map value="no-gen-base"/>
      </mapping>
    </element>
    <element id="StructureDefinition.version">
      <path value="StructureDefinition.version"/>
      <short value="Business version of the structure definition"/>
      <definition
                  value="The identifier that is used to identify this version of the structure definition when it is referenced in a specification, model, design or instance. This is an arbitrary value managed by the structure definition author and is not expected to be globally unique. There is no expectation that versions can be placed in a lexicographical sequence, so authors are encouraged to populate the StructureDefinition.versionAlgorithm[x] element to enable comparisons. If there is no managed version available, authors can consider using ISO date/time syntax (e.g., '2023-01-01')."/>
      <comment
               value="There may be different structure definition instances that have the same identifier but different versions.  The version can be appended to the url in a reference to allow a reference to a particular business version of the structure definition with the format [url]|[version]. The version SHOULD NOT contain a '#' - see [Business Version](http://hl7.org/fhir/R5/resource.html#bv-format)."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.version"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="string"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.version"/>
      </mapping>
      <mapping>
        <identity value="iso11179"/>
        <map value="Version"/>
      </mapping>
    </element>
    <element id="StructureDefinition.versionAlgorithm[x]">
      <path value="StructureDefinition.versionAlgorithm[x]"/>
      <short value="How to compare versions"/>
      <definition
                  value="Indicates the mechanism used to compare versions to determine which is more current."/>
      <comment
               value="If set as a string, this is a FHIRPath expression that has two additional context variables passed in - %version1 and %version2 and will return a negative number if version1 is newer, a positive number if version2 and a 0 if the version ordering can't be successfully be determined."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.versionAlgorithm[x]"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="string"/>
      </type>
      <type>
        <code value="Coding"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <binding>
        <strength value="extensible"/>
        <valueSet value="http://hl7.org/fhir/ValueSet/version-algorithm"/>
      </binding>
    </element>
    <element id="StructureDefinition.name">
      <path value="StructureDefinition.name"/>
      <short value="Name for this structure definition (computer friendly)"/>
      <definition
                  value="A natural language name identifying the structure definition. This name should be usable as an identifier for the module by machine processing applications such as code generation."/>
      <comment
               value="The name is not expected to be globally unique. The name should be a simple alphanumeric type name to ensure that it is machine-processing friendly.Some Examples: 

* O2SatObservation
* PresentationReport
* Immunization2
* AcmeAdmissionRecordOld."/>
      <requirements value="Support human navigation and code generation."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.name"/>
        <min value="1"/>
        <max value="1"/>
      </base>
      <type>
        <code value="string"/>
      </type>
      <condition value="cnl-0"/>
      <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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="StructureDefinition.title">
      <extension
                 url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/>
      </extension>
      <extension
                 url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/>
      </extension>
      <path value="StructureDefinition.title"/>
      <short value="Name for this structure definition (human friendly)"/>
      <definition
                  value="A short, descriptive, user-friendly title for the structure definition."/>
      <comment
               value="This name does not need to be machine-processing friendly and may contain punctuation, white-space, etc.Applications don't have to use this name but can always fall back to it. The title also corresponds to the label for the root element."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.title"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="string"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="StructureDefinition.status">
      <path value="StructureDefinition.status"/>
      <short value="draft | active | retired | unknown"/>
      <definition
                  value="The status of this structure definition. Enables tracking the life-cycle of the content."/>
      <comment
               value="Allows filtering of structure definitions that are appropriate for use versus not.

See guidance around (not) making local changes to elements [here](http://hl7.org/fhir/R5/canonicalresource.html#localization)."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.status"/>
        <min value="1"/>
        <max value="1"/>
      </base>
      <type>
        <code value="code"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="true"/>
      <isModifierReason
                        value="This is labeled as &quot;Is Modifier&quot; because applications should not use a retired {{title}} without due consideration"/>
      <isSummary value="true"/>
      <binding>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="PublicationStatus"/>
        </extension>
        <strength value="required"/>
        <description value="The lifecycle status of an artifact."/>
        <valueSet
                  value="http://hl7.org/fhir/ValueSet/publication-status|5.0.0"/>
      </binding>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.status"/>
      </mapping>
      <mapping>
        <identity value="iso11179"/>
        <map value="Registration status"/>
      </mapping>
    </element>
    <element id="StructureDefinition.experimental">
      <path value="StructureDefinition.experimental"/>
      <short value="For testing purposes, not real usage"/>
      <definition
                  value="A Boolean value to indicate that this structure definition is authored for testing purposes (or education/evaluation/marketing) and is not intended to be used for genuine usage."/>
      <comment
               value="Allows filtering of structure definitions that are appropriate for use versus not."/>
      <requirements
                    value="Enables experimental content to be developed following the same lifecycle that would be used for a production-level structure definition."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.experimental"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="boolean"/>
      </type>
      <meaningWhenMissing
                          value="If absent, this resource is treated as though it is not experimental."/>
      <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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.class"/>
      </mapping>
      <mapping>
        <identity value="iso11179"/>
        <map value="Registration status"/>
      </mapping>
    </element>
    <element id="StructureDefinition.date">
      <path value="StructureDefinition.date"/>
      <short value="Date last changed"/>
      <definition
                  value="The date  (and optionally time) when the structure definition was last significantly changed. The date must change when the business version changes and it must change if the status code changes. In addition, it should change when the substantive content of the structure definition changes."/>
      <comment
               value="The date is often not tracked until the resource is published, but may be present on draft content. Note that this is not the same as the resource last-modified-date, since the resource may be a secondary representation of the structure definition. Additional specific dates may be added as extensions or be found by consulting Provenances associated with past versions of the resource.

See guidance around (not) making local changes to elements [here](http://hl7.org/fhir/R5/canonicalresource.html#localization)."/>
      <alias value="Revision Date"/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.date"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="dateTime"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.recorded"/>
      </mapping>
    </element>
    <element id="StructureDefinition.publisher">
      <extension
                 url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/>
      </extension>
      <extension
                 url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/>
      </extension>
      <path value="StructureDefinition.publisher"/>
      <short
             value="Name of the publisher/steward (organization or individual)"/>
      <definition
                  value="The name of the organization or individual responsible for the release and ongoing maintenance of the structure definition."/>
      <comment
               value="Usually an organization but may be an individual. The publisher (or steward) of the structure definition is the organization or individual primarily responsible for the maintenance and upkeep of the structure definition. This is not necessarily the same individual or organization that developed and initially authored the content. The publisher is the primary point of contact for questions or issues with the structure definition. This item SHOULD be populated unless the information is available from context."/>
      <requirements
                    value="Helps establish the &quot;authority/credibility&quot; of the structure definition.  May also allow for contact."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.publisher"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="string"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.witness"/>
      </mapping>
      <mapping>
        <identity value="iso11179"/>
        <map value="Registration Authority"/>
      </mapping>
    </element>
    <element id="StructureDefinition.contact">
      <path value="StructureDefinition.contact"/>
      <short value="Contact details for the publisher"/>
      <definition
                  value="Contact details to assist a user in finding and communicating with the publisher."/>
      <comment
               value="May be a web site, an email address, a telephone number, etc.

See guidance around (not) making local changes to elements [here](http://hl7.org/fhir/R5/canonicalresource.html#localization)."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="StructureDefinition.contact"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="ContactDetail"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="StructureDefinition.description">
      <extension
                 url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/>
      </extension>
      <extension
                 url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/>
      </extension>
      <path value="StructureDefinition.description"/>
      <short
             value="Natural language description of the structure definition"/>
      <definition
                  value="A free text natural language description of the structure definition from a consumer's perspective."/>
      <comment
               value="This description can be used to capture details such as comments about misuse, instructions for clinical use and interpretation, literature references, examples from the paper world, etc. It is not a rendering of the structure definition as conveyed in the 'text' field of the resource itself. This item SHOULD be populated unless the information is available from context (e.g. the language of the structure definition is presumed to be the predominant language in the place the structure definition was created)."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.description"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="markdown"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
    <element id="StructureDefinition.useContext">
      <path value="StructureDefinition.useContext"/>
      <short value="The context that the content is intended to support"/>
      <definition
                  value="The content was developed with a focus and intent of supporting the contexts that are listed. These contexts may be general categories (gender, age, ...) or may be references to specific programs (insurance plans, studies, ...) and may be used to assist with indexing and searching for appropriate structure definition instances."/>
      <comment
               value="When multiple useContexts are specified, there is no expectation that all or any of the contexts apply."/>
      <requirements value="Assist in searching for appropriate content."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="StructureDefinition.useContext"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="UsageContext"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="StructureDefinition.jurisdiction">
      <path value="StructureDefinition.jurisdiction"/>
      <short
             value="Intended jurisdiction for structure definition (if applicable)"/>
      <definition
                  value="A legal or geographic region in which the structure definition is intended to be used."/>
      <comment
               value="It may be possible for the structure definition to be used in jurisdictions other than those for which it was originally designed or intended.

DEPRECATION NOTE: For consistency, implementations are encouraged to migrate to using the new 'jurisdiction' code in the useContext element.  (I.e. useContext.code indicating http://terminology.hl7.org/CodeSystem/usage-context-type#jurisdiction and useContext.valueCodeableConcept indicating the jurisdiction.)"/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="StructureDefinition.jurisdiction"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="CodeableConcept"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <binding>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="Jurisdiction"/>
        </extension>
        <strength value="extensible"/>
        <description
                     value="Countries and regions within which this artifact is targeted for use."/>
        <valueSet value="http://hl7.org/fhir/ValueSet/jurisdiction"/>
      </binding>
    </element>
    <element id="StructureDefinition.purpose">
      <extension
                 url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/>
      </extension>
      <extension
                 url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/>
      </extension>
      <path value="StructureDefinition.purpose"/>
      <short value="Why this structure definition is defined"/>
      <definition
                  value="Explanation of why this structure definition is needed and why it has been designed as it has."/>
      <comment
               value="This element does not describe the usage of the structure definition. Instead, it provides traceability of ''why'' the resource is either needed or ''why'' it is defined as it is.  This may be used to point to source materials or specifications that drove the structure of this structure definition."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.purpose"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="markdown"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.why[x]"/>
      </mapping>
      <mapping>
        <identity value="objimpl"/>
        <map value="no-gen-base"/>
      </mapping>
    </element>
    <element id="StructureDefinition.copyright">
      <extension
                 url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/>
      </extension>
      <extension
                 url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/>
      </extension>
      <path value="StructureDefinition.copyright"/>
      <short value="Use and/or publishing restrictions"/>
      <definition
                  value="A copyright statement relating to the structure definition and/or its contents. Copyright statements are generally legal restrictions on the use and publishing of the structure definition.  The short copyright declaration (e.g. (c) '2015+ xyz organization' should be sent in the copyrightLabel element."/>
      <comment value="..."/>
      <requirements
                    value="Consumers must be able to determine any legal restrictions on the use of the structure definition and/or its content."/>
      <alias value="License"/>
      <alias value="Restrictions"/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.copyright"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="markdown"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="objimpl"/>
        <map value="no-gen-base"/>
      </mapping>
    </element>
    <element id="StructureDefinition.copyrightLabel">
      <extension
                 url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/>
      </extension>
      <extension
                 url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/>
      </extension>
      <path value="StructureDefinition.copyrightLabel"/>
      <short value="Copyright holder and year(s)"/>
      <definition
                  value="A short string (&lt;50 characters), suitable for inclusion in a page footer that identifies the copyright holder, effective period, and optionally whether rights are resctricted. (e.g. 'All rights reserved', 'Some rights reserved')."/>
      <comment
               value="The (c) symbol should NOT be included in this string. It will be added by software when rendering the notation. Full details about licensing, restrictions, warrantees, etc. goes in the more general 'copyright' element."/>
      <requirements
                    value="Defines the content expected to be rendered in all representations of the artifact."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.copyrightLabel"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="string"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
    <element id="StructureDefinition.keyword">
      <path value="StructureDefinition.keyword"/>
      <short value="Assist with indexing and finding"/>
      <definition
                  value="(DEPRECATED) A set of key words or terms from external terminologies that may be used to assist with indexing and searching of templates nby describing the use of this structure definition, or the content it describes."/>
      <comment
               value="Note that this element is deprecated. Use the [http://hl7.org/fhir/StructureDefinition/artifact-topic](http://hl7.org/fhir/extensions/StructureDefinition-artifact-topic.html) extension instead."/>
      <requirements
                    value="Assist in searching for appropriate StructureDefinitions."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="StructureDefinition.keyword"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="Coding"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <binding>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="StructureDefinitionKeyword"/>
        </extension>
        <strength value="extensible"/>
        <description
                     value="Codes for the meaning of the defined structure (SNOMED CT and LOINC codes, as an example)."/>
        <valueSet value="http://hl7.org/fhir/ValueSet/definition-use"/>
      </binding>
      <mapping>
        <identity value="iso11179"/>
        <map value="keywords"/>
      </mapping>
    </element>
    <element id="StructureDefinition.fhirVersion">
      <path value="StructureDefinition.fhirVersion"/>
      <short value="FHIR Version this StructureDefinition targets"/>
      <definition
                  value="The version of the FHIR specification on which this StructureDefinition is based - this is the formal version of the specification, without the revision number, e.g. [publication].[major].[minor], which is 4.6.0. for this version."/>
      <comment
               value="A StructureDefinition does not need to specify the target it applies to as StructureDefinitions will often be valid across multiple versions of FHIR. FHIR tooling can determine whether a StructureDefinition is consistent with a particular StructureDefinition if desired."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.fhirVersion"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="code"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <binding>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="FHIRVersion"/>
        </extension>
        <strength value="required"/>
        <description value="All published FHIR Versions."/>
        <valueSet value="http://hl7.org/fhir/ValueSet/FHIR-version|5.0.0"/>
      </binding>
    </element>
    <element id="StructureDefinition.mapping">
      <path value="StructureDefinition.mapping"/>
      <short value="External specification that the content is mapped to"/>
      <definition
                  value="An external specification that the content is mapped to."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="StructureDefinition.mapping"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="BackboneElement"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <constraint>
        <key value="sdf-2"/>
        <severity value="error"/>
        <human value="Must have at least a name or a uri (or both)"/>
        <expression value="name.exists() or uri.exists()"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
    <element id="StructureDefinition.mapping.id">
      <path value="StructureDefinition.mapping.id"/>
      <representation value="xmlAttr"/>
      <short value="Unique id for inter-element referencing"/>
      <definition
                  value="Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces."/>
      <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>
      <condition value="ele-1"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="n/a"/>
      </mapping>
    </element>
    <element id="StructureDefinition.mapping.extension">
      <path value="StructureDefinition.mapping.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 element. To make the use of extensions safe and managable, 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())"/>
        <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()"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="n/a"/>
      </mapping>
    </element>
    <element id="StructureDefinition.mapping.modifierExtension">
      <path value="StructureDefinition.mapping.modifierExtension"/>
      <short value="Extensions that cannot be ignored even if unrecognized"/>
      <definition
                  value="May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and managable, 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. Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself)."/>
      <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."/>
      <requirements
                    value="Modifier extensions allow for extensions that *cannot* be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored.  This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the [definition of modifier extensions](http://hl7.org/fhir/R5/extensibility.html#modifierExtension)."/>
      <alias value="extensions"/>
      <alias value="user content"/>
      <alias value="modifiers"/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="BackboneElement.modifierExtension"/>
        <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())"/>
        <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()"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/>
      </constraint>
      <isModifier value="true"/>
      <isModifierReason
                        value="Modifier extensions are expected to modify the meaning or interpretation of the element that contains them"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="rim"/>
        <map value="N/A"/>
      </mapping>
    </element>
    <element id="StructureDefinition.mapping.identity">
      <path value="StructureDefinition.mapping.identity"/>
      <short value="Internal id when this mapping is used"/>
      <definition
                  value="An Internal id that is used to identify this mapping set when specific mappings are made."/>
      <comment
               value="The specification is described once, with general comments, and then specific mappings are made that reference this declaration."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.mapping.identity"/>
        <min value="1"/>
        <max value="1"/>
      </base>
      <type>
        <code value="id"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
    <element id="StructureDefinition.mapping.uri">
      <path value="StructureDefinition.mapping.uri"/>
      <short value="Identifies what this mapping refers to"/>
      <definition
                  value="An absolute URI that identifies the specification that this mapping is expressed to."/>
      <comment
               value="A formal identity for the specification being mapped to helps with identifying maps consistently."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.mapping.uri"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="uri"/>
      </type>
      <condition value="sdf-2"/>
      <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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
    <element id="StructureDefinition.mapping.name">
      <path value="StructureDefinition.mapping.name"/>
      <short value="Names what this mapping refers to"/>
      <definition
                  value="A name for the specification that is being mapped to."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.mapping.name"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="string"/>
      </type>
      <condition value="sdf-2"/>
      <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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
    <element id="StructureDefinition.mapping.comment">
      <path value="StructureDefinition.mapping.comment"/>
      <short value="Versions, Issues, Scope limitations etc"/>
      <definition
                  value="Comments about this mapping, including version notes, issues, scope limitations, and other important notes for usage."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.mapping.comment"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="string"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
    <element id="StructureDefinition.kind">
      <path value="StructureDefinition.kind"/>
      <short value="primitive-type | complex-type | resource | logical"/>
      <definition
                  value="Defines the kind of structure that this definition is describing."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.kind"/>
        <min value="1"/>
        <max value="1"/>
      </base>
      <type>
        <code value="code"/>
      </type>
      <fixedCode value="primitive-type"/>
      <condition value="sdf-15a"/>
      <condition value="sdf-15"/>
      <condition value="sdf-11"/>
      <condition value="sdf-29"/>
      <condition value="sdf-8"/>
      <condition value="sdf-3"/>
      <condition value="sdf-8a"/>
      <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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <binding>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="StructureDefinitionKind"/>
        </extension>
        <strength value="required"/>
        <description
                     value="Defines the type of structure that a definition is describing."/>
        <valueSet
                  value="http://hl7.org/fhir/ValueSet/structure-definition-kind|5.0.0"/>
      </binding>
    </element>
    <element id="StructureDefinition.abstract">
      <path value="StructureDefinition.abstract"/>
      <short value="Whether the structure is abstract"/>
      <definition
                  value="Whether structure this definition describes is abstract or not  - that is, whether the structure is not intended to be instantiated. For Resources and Data types, abstract types will never be exchanged  between systems."/>
      <comment
               value="Abstract Resources cannot be instantiated - a concrete sub-type must be used. Abstract datatypes and extensions cannot be used in an instance. For logical models, the exact implication of &quot;abstract&quot; will rest with the author, depending how the logical model is used. Flagging a constraint structure as abstract conveys design intent but makes no difference to how the structure definition is handled. Note that inline declared elements that are given the type &quot;Element&quot; in the StructureDefinition, but have children described, are anonymous concrete types that specialize Element."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.abstract"/>
        <min value="1"/>
        <max value="1"/>
      </base>
      <type>
        <code value="boolean"/>
      </type>
      <fixedBoolean value="false"/>
      <condition value="sdf-4"/>
      <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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="StructureDefinition.context">
      <path value="StructureDefinition.context"/>
      <short value="If an extension, where it can be used in instances"/>
      <definition
                  value="Identifies the types of resource or data type elements to which the extension can be applied. For more guidance on using the 'context' element, see the [defining extensions page](http://hl7.org/fhir/R5/defining-extensions.html#context)."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="StructureDefinition.context"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="BackboneElement"/>
      </type>
      <condition value="sdf-5"/>
      <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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="StructureDefinition.context.id">
      <path value="StructureDefinition.context.id"/>
      <representation value="xmlAttr"/>
      <short value="Unique id for inter-element referencing"/>
      <definition
                  value="Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces."/>
      <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>
      <condition value="ele-1"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="n/a"/>
      </mapping>
    </element>
    <element id="StructureDefinition.context.extension">
      <path value="StructureDefinition.context.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 element. To make the use of extensions safe and managable, 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())"/>
        <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()"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="n/a"/>
      </mapping>
    </element>
    <element id="StructureDefinition.context.modifierExtension">
      <path value="StructureDefinition.context.modifierExtension"/>
      <short value="Extensions that cannot be ignored even if unrecognized"/>
      <definition
                  value="May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and managable, 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. Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself)."/>
      <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."/>
      <requirements
                    value="Modifier extensions allow for extensions that *cannot* be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored.  This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the [definition of modifier extensions](http://hl7.org/fhir/R5/extensibility.html#modifierExtension)."/>
      <alias value="extensions"/>
      <alias value="user content"/>
      <alias value="modifiers"/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="BackboneElement.modifierExtension"/>
        <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())"/>
        <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()"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/>
      </constraint>
      <isModifier value="true"/>
      <isModifierReason
                        value="Modifier extensions are expected to modify the meaning or interpretation of the element that contains them"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="rim"/>
        <map value="N/A"/>
      </mapping>
    </element>
    <element id="StructureDefinition.context.type">
      <path value="StructureDefinition.context.type"/>
      <short value="fhirpath | element | extension"/>
      <definition
                  value="Defines how to interpret the expression that defines what the context of the extension is."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.context.type"/>
        <min value="1"/>
        <max value="1"/>
      </base>
      <type>
        <code value="code"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <binding>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="ExtensionContextType"/>
        </extension>
        <strength value="required"/>
        <description value="How an extension context is interpreted."/>
        <valueSet
                  value="http://hl7.org/fhir/ValueSet/extension-context-type|5.0.0"/>
      </binding>
    </element>
    <element id="StructureDefinition.context.expression">
      <path value="StructureDefinition.context.expression"/>
      <short value="Where the extension can be used in instances"/>
      <definition
                  value="An expression that defines where an extension can be used in resources."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.context.expression"/>
        <min value="1"/>
        <max value="1"/>
      </base>
      <type>
        <code value="string"/>
      </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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="StructureDefinition.contextInvariant">
      <path value="StructureDefinition.contextInvariant"/>
      <short value="FHIRPath invariants - when the extension can be used"/>
      <definition
                  value="A set of rules as FHIRPath Invariants about when the extension can be used (e.g. co-occurrence variants for the extension). All the rules must be true."/>
      <comment
               value="The rules are only evaluated when the extension is present. When evaluating the invariant, the FHIRPath focus is the element that holds the extension, and %extension refers to the extension itself."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="StructureDefinition.contextInvariant"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="string"/>
      </type>
      <condition value="sdf-18"/>
      <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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="StructureDefinition.type">
      <path value="StructureDefinition.type"/>
      <short value="Type defined or constrained by this structure"/>
      <definition
                  value="The type this structure describes. If the derivation kind is 'specialization' then this is the master definition for a type, and there is always one of these (a data type, an extension, a resource, including abstract ones). Otherwise the structure definition is a constraint on the stated type (and in this case, the type cannot be an abstract type).  References are URLs that are relative to http://hl7.org/fhir/StructureDefinition e.g. &quot;string&quot; is a reference to http://hl7.org/fhir/StructureDefinition/string. Absolute URLs are only allowed in logical models, where they are required."/>
      <comment
               value="Note that in the case of constraints, the type could be determined by chasing through the baseDefinition references until a type defining structure (derivation = specialization) is reached, or by looking at the path of the first element in the snapshot - if present - but providing the type directly makes for simpler tooling and indexing. 

The type must match the elements defined in the differential and the snapshot. For all FHIR defined types, the path name of the element will start with the type name. For logical models, where the type SHALL be a fully specified URL, the type name SHOULD start with the final path segment of the type URL where required. E.g. If the type was &quot;http://example.org/fhir/MyLogicalModelType&quot;, the type name should start with 'MyLogicalModelType'."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.type"/>
        <min value="1"/>
        <max value="1"/>
      </base>
      <type>
        <code value="uri"/>
      </type>
      <condition value="sdf-18"/>
      <condition value="sdf-11"/>
      <condition value="sdf-5"/>
      <condition value="sdf-8"/>
      <condition value="sdf-8a"/>
      <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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <binding>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="FHIRTypes"/>
        </extension>
        <strength value="extensible"/>
        <description
                     value="Either a resource or a data type, including logical model types."/>
        <valueSet value="http://hl7.org/fhir/ValueSet/fhir-types"/>
      </binding>
    </element>
    <element id="StructureDefinition.baseDefinition">
      <path value="StructureDefinition.baseDefinition"/>
      <short
             value="Definition that this type is constrained/specialized from"/>
      <definition
                  value="An absolute URI that is the base structure from which this type is derived, either by specialization or constraint."/>
      <comment
               value="If differential constraints are specified in this structure, they are applied to the base in a &quot;differential&quot; fashion. If there is no base, then the differential constraints cannot be provided (snapshot only). Differential structures are useful for the editing perspective, and snapshot structures are suitable for operational use. The FHIR Project provides a number of tools/services to populate snapshots from differential constraints. Logical Models have a base of &quot;Base&quot;, &quot;Element&quot; or another logical model."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.baseDefinition"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/structuredefinition-hierarchy">
          <valueBoolean value="true"/>
        </extension>
        <code value="canonical"/>
        <targetProfile
                       value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </type>
      <condition value="sdf-4"/>
      <condition value="sdf-27"/>
      <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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="StructureDefinition.derivation">
      <path value="StructureDefinition.derivation"/>
      <short
             value="specialization | constraint - How relates to base definition"/>
      <definition value="How the type relates to the baseDefinition."/>
      <comment
               value="If the definition is a specialization, then it adds to the differential new elements and optionally additional rules to an existing concrete type, and the snapshot includes the inherited elements and rules.  If the definition is a constraint, then it cannot define new elements, it can only make new rules about existing content (see [Profiling Resources](http://hl7.org/fhir/R5/profiling.html#resources))."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.derivation"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="code"/>
      </type>
      <fixedCode value="constraint"/>
      <condition value="sdf-1"/>
      <condition value="sdf-21"/>
      <condition value="sdf-5"/>
      <condition value="sdf-27"/>
      <condition value="sdf-29"/>
      <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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <binding>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="TypeDerivationRule"/>
        </extension>
        <strength value="required"/>
        <description value="How a type relates to its baseDefinition."/>
        <valueSet
                  value="http://hl7.org/fhir/ValueSet/type-derivation-rule|5.0.0"/>
      </binding>
    </element>
    <element id="StructureDefinition.snapshot">
      <path value="StructureDefinition.snapshot"/>
      <short value="Snapshot view of the structure"/>
      <definition
                  value="A snapshot view is expressed in a standalone form that can be used and interpreted without considering the base StructureDefinition."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.snapshot"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="BackboneElement"/>
      </type>
      <condition value="sdf-11"/>
      <condition value="sdf-1"/>
      <condition value="sdf-6"/>
      <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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <constraint>
        <key value="sdf-3"/>
        <severity value="error"/>
        <human
               value="Each element definition in a snapshot must have a formal definition and cardinalities, unless model is a logical model"/>
        <expression
                    value="%resource.kind = 'logical' or element.all(definition.exists() and min.exists() and max.exists())"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-8"/>
        <severity value="error"/>
        <human
               value="All snapshot elements must start with the StructureDefinition's specified type for non-logical models, or with the same type name for logical models"/>
        <expression
                    value="(%resource.kind = 'logical' or element.first().path = %resource.type) and element.tail().all(path.startsWith(%resource.snapshot.element.first().path&amp;'.'))"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-24"/>
        <severity value="error"/>
        <human
               value="For CodeableReference elements, target profiles must be listed on the CodeableReference, not the CodeableReference.reference"/>
        <expression
                    value="element.where(type.where(code='Reference').exists() and path.endsWith('.reference') and type.targetProfile.exists() and (path.substring(0,$this.path.length()-10) in %context.element.where(type.where(code='CodeableReference').exists()).path)).exists().not()"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-25"/>
        <severity value="error"/>
        <human
               value="For CodeableReference elements, bindings must be listed on the CodeableReference, not the CodeableReference.concept"/>
        <expression
                    value="element.where(type.where(code='CodeableConcept').exists() and path.endsWith('.concept') and binding.exists() and (path.substring(0,$this.path.length()-8) in %context.element.where(type.where(code='CodeableReference').exists()).path)).exists().not()"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bestpractice">
          <valueBoolean value="true"/>
        </extension>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bestpractice-explanation">
          <valueMarkdown
                         value="It is bad practice to set the root element of a profile to 'mustSupport' as mustSupport should always be determined by the element referencing a type.  The designer of a StructureDefinition cannot know all circumstances in which a type or profile might be used"/>
        </extension>
        <key value="sdf-26"/>
        <severity value="warning"/>
        <human
               value="The root element of a profile should not have mustSupport = true"/>
        <expression
                    value="$this.where(element[0].mustSupport='true').exists().not()"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-8b"/>
        <severity value="error"/>
        <human value="All snapshot elements must have a base definition"/>
        <expression value="element.all(base.exists())"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
    <element id="StructureDefinition.snapshot.id">
      <path value="StructureDefinition.snapshot.id"/>
      <representation value="xmlAttr"/>
      <short value="Unique id for inter-element referencing"/>
      <definition
                  value="Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces."/>
      <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>
      <condition value="ele-1"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="n/a"/>
      </mapping>
    </element>
    <element id="StructureDefinition.snapshot.extension">
      <path value="StructureDefinition.snapshot.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 element. To make the use of extensions safe and managable, 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())"/>
        <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()"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="n/a"/>
      </mapping>
    </element>
    <element id="StructureDefinition.snapshot.modifierExtension">
      <path value="StructureDefinition.snapshot.modifierExtension"/>
      <short value="Extensions that cannot be ignored even if unrecognized"/>
      <definition
                  value="May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and managable, 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. Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself)."/>
      <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."/>
      <requirements
                    value="Modifier extensions allow for extensions that *cannot* be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored.  This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the [definition of modifier extensions](http://hl7.org/fhir/R5/extensibility.html#modifierExtension)."/>
      <alias value="extensions"/>
      <alias value="user content"/>
      <alias value="modifiers"/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="BackboneElement.modifierExtension"/>
        <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())"/>
        <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()"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/>
      </constraint>
      <isModifier value="true"/>
      <isModifierReason
                        value="Modifier extensions are expected to modify the meaning or interpretation of the element that contains them"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="rim"/>
        <map value="N/A"/>
      </mapping>
    </element>
    <element id="StructureDefinition.snapshot.element">
      <path value="StructureDefinition.snapshot.element"/>
      <short
             value="Definition of elements in the resource (if no StructureDefinition)"/>
      <definition
                  value="Captures constraints on each element within the resource."/>
      <min value="1"/>
      <max value="*"/>
      <base>
        <path value="StructureDefinition.snapshot.element"/>
        <min value="1"/>
        <max value="*"/>
      </base>
      <type>
        <code value="ElementDefinition"/>
      </type>
      <condition value="sdf-9"/>
      <condition value="sdf-19"/>
      <condition value="sdf-16"/>
      <condition value="sdf-15"/>
      <condition value="sdf-23"/>
      <condition value="sdf-11"/>
      <condition value="sdf-22"/>
      <condition value="sdf-14"/>
      <condition value="sdf-1"/>
      <condition value="sdf-8"/>
      <condition value="sdf-3"/>
      <condition value="sdf-8b"/>
      <condition value="sdf-24"/>
      <condition value="sdf-25"/>
      <condition value="sdf-26"/>
      <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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <constraint>
        <key value="sdf-10"/>
        <requirements value="binding is required"/>
        <severity value="error"/>
        <human
               value="provide either a binding reference or a description (or both)"/>
        <expression
                    value="binding.empty() or binding.valueSet.exists() or binding.description.exists()"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-28"/>
        <severity value="error"/>
        <human
               value="If there are no discriminators, there must be a definition"/>
        <expression
                    value="slicing.exists().not() or (slicing.discriminator.exists() or slicing.description.exists())"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="iso11179"/>
        <map value="--"/>
      </mapping>
    </element>
    <element id="StructureDefinition.differential">
      <path value="StructureDefinition.differential"/>
      <short value="Differential view of the structure"/>
      <definition
                  value="A differential view is expressed relative to the base StructureDefinition - a statement of differences that it applies."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="StructureDefinition.differential"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="BackboneElement"/>
      </type>
      <condition value="sdf-6"/>
      <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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <constraint>
        <key value="sdf-20"/>
        <requirements value="no slicing on root"/>
        <severity value="error"/>
        <human value="No slicing on the root element"/>
        <expression
                    value="element.where(path.contains('.').not()).slicing.empty()"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <constraint>
        <key value="sdf-8a"/>
        <severity value="error"/>
        <human
               value="In any differential, all the elements must start with the StructureDefinition's specified type for non-logical models, or with the same type name for logical models"/>
        <expression
                    value="(%resource.kind = 'logical' or element.first().path.startsWith(%resource.type)) and (element.tail().empty() or  element.tail().all(path.startsWith(%resource.differential.element.first().path.replaceMatches('\\..*','')&amp;'.')))"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
    <element id="StructureDefinition.differential.id">
      <path value="StructureDefinition.differential.id"/>
      <representation value="xmlAttr"/>
      <short value="Unique id for inter-element referencing"/>
      <definition
                  value="Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces."/>
      <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>
      <condition value="ele-1"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="n/a"/>
      </mapping>
    </element>
    <element id="StructureDefinition.differential.extension">
      <path value="StructureDefinition.differential.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 element. To make the use of extensions safe and managable, 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())"/>
        <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()"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="n/a"/>
      </mapping>
    </element>
    <element id="StructureDefinition.differential.modifierExtension">
      <path value="StructureDefinition.differential.modifierExtension"/>
      <short value="Extensions that cannot be ignored even if unrecognized"/>
      <definition
                  value="May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and managable, 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. Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself)."/>
      <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."/>
      <requirements
                    value="Modifier extensions allow for extensions that *cannot* be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored.  This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the [definition of modifier extensions](http://hl7.org/fhir/R5/extensibility.html#modifierExtension)."/>
      <alias value="extensions"/>
      <alias value="user content"/>
      <alias value="modifiers"/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="BackboneElement.modifierExtension"/>
        <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())"/>
        <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()"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/>
      </constraint>
      <isModifier value="true"/>
      <isModifierReason
                        value="Modifier extensions are expected to modify the meaning or interpretation of the element that contains them"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="rim"/>
        <map value="N/A"/>
      </mapping>
    </element>
    <element id="StructureDefinition.differential.element">
      <path value="StructureDefinition.differential.element"/>
      <short
             value="Definition of elements in the resource (if no StructureDefinition)"/>
      <definition
                  value="Captures constraints on each element within the resource."/>
      <min value="1"/>
      <max value="*"/>
      <base>
        <path value="StructureDefinition.differential.element"/>
        <min value="1"/>
        <max value="*"/>
      </base>
      <type>
        <code value="ElementDefinition"/>
      </type>
      <condition value="sdf-9"/>
      <condition value="sdf-15a"/>
      <condition value="sdf-19"/>
      <condition value="sdf-17"/>
      <condition value="sdf-23"/>
      <condition value="sdf-22"/>
      <condition value="sdf-14"/>
      <condition value="sdf-21"/>
      <condition value="sdf-29"/>
      <condition value="sdf-20"/>
      <condition value="sdf-8a"/>
      <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())"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="iso11179"/>
        <map value="--"/>
      </mapping>
    </element>
  </snapshot>
  <differential>
    <element id="StructureDefinition">
      <path value="StructureDefinition"/>
    </element>
    <element id="StructureDefinition.url">
      <path value="StructureDefinition.url"/>
      <binding>
        <strength value="required"/>
        <valueSet
                  value="http://hl7.org/v2/ValueSet/v2-vs-primitive-data-type-urls"/>
      </binding>
    </element>
    <element id="StructureDefinition.kind">
      <path value="StructureDefinition.kind"/>
      <fixedCode value="primitive-type"/>
    </element>
    <element id="StructureDefinition.abstract">
      <path value="StructureDefinition.abstract"/>
      <fixedBoolean value="false"/>
    </element>
    <element id="StructureDefinition.derivation">
      <path value="StructureDefinition.derivation"/>
      <fixedCode value="constraint"/>
    </element>
  </differential>
</StructureDefinition>