HL7 FHIR® Implementation Guide: Electronic Case Reporting (eCR) - US Realm
2.0.0 - STU 2

This page is part of the electronic Case Reporting (eCR) (v2.0.0: STU 2 on FHIR R4) based on FHIR R4. The current version which supercedes this version is 2.1.0. For a full list of available versions, see the Directory of published versions

Resource Profile: USPublicHealthCodeSystem - XML Profile

XML representation of the us-ph-codesystem resource profile.

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<StructureDefinition xmlns="http://hl7.org/fhir">
  <id value="us-ph-codesystem"/>
  <meta>
    <versionId value="8"/>
    <lastUpdated value="2021-06-30T23:50:55.316+00:00"/>
    <source value="#SH0oUTnGUbsLUhuL"/>
  </meta>
  <text>
    <status value="extensions"/>
    <div xmlns="http://www.w3.org/1999/xhtml"><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="http://hl7.org/fhir/R4/formats.html#table" 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="http://hl7.org/fhir/R4/formats.html#table" 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="http://hl7.org/fhir/R4/formats.html#table" title="Minimum and Maximum # of times the the element can appear in the instance">Card.</a></th><th style="width: 100px" class="hierarchy"><a href="http://hl7.org/fhir/R4/formats.html#table" 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="http://hl7.org/fhir/R4/formats.html#table" title="Additional information about the element">Description &amp; Constraints</a><span style="float: right"><a href="http://hl7.org/fhir/R4/formats.html#table" title="Legend for this format"><img src="http://hl7.org/fhir/R4/help16.png" 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-us-ph-codesystem-definitions.html#CodeSystem">CodeSystem</a><a name="CodeSystem"> </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/R4/codesystem.html">CodeSystem</a></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy">US Public Health CodeSystem</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_bck01.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: #F7F7F7; background-color: inherit" title="Element" class="hierarchy"/> <a href="StructureDefinition-us-ph-codesystem-definitions.html#CodeSystem.property">property</a><a name="CodeSystem.property"> </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="padding-left: 3px; padding-right: 3px; color: white; background-color: red" title="This element must be supported">S</span></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">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: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a style="opacity: 0.5" href="http://hl7.org/fhir/R4/datatypes.html#BackboneElement">BackboneElement</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">Additional information supplied about each concept</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_bck004.png)" class="hierarchy"><img src="tbl_spacer.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="tbl_blank.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="tbl_vjoin_end.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="icon_slice_item.png" alt="." style="background-color: white; background-color: inherit" title="Slice Item" class="hierarchy"/> <a href="StructureDefinition-us-ph-codesystem-definitions.html#CodeSystem.property.extension:binding" title="Extension URL = http://hl7.org/fhir/us/ecr/StructureDefinition/us-ph-codesystem-property-binding-extension">us-ph-codesystem-property-binding-extension</a><a name="CodeSystem.property.extension"> </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="padding-left: 3px; padding-right: 3px; color: white; background-color: red" title="This element must be supported">S</span></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy">0..1</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/R4/references.html">canonical</a>()</td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy">What values are allowed<br/><span style="font-weight:bold">URL: </span><a href="http://hl7.org/fhir/R4/StructureDefinition-us-ph-codesystem-property-binding-extension.html">http://hl7.org/fhir/us/ecr/StructureDefinition/us-ph-codesystem-property-binding-extension</a></td></tr>
<tr><td colspan="5" class="hierarchy"><br/><a href="http://hl7.org/fhir/R4/formats.html#table" title="Legend for this format"><img src="http://hl7.org/fhir/R4/help16.png" alt="doco" style="background-color: inherit"/> Documentation for this format</a></td></tr></table></div>
  </text>
  <url value="http://hl7.org/fhir/us/ecr/StructureDefinition/us-ph-codesystem"/>
  <version value="2.0.0"/>
  <name value="USPublicHealthCodeSystem"/>
  <title value="US Public Health CodeSystem"/>
  <status value="active"/>
  <date value="2022-01-18T12:57:33+00:00"/>
  <publisher
             value="HL7 Public Health Work Group (http://www.hl7.org/Special/committees/pher/index.cfm)"/>
  <contact>
    <name value="HL7 International - Public Health"/>
    <telecom>
      <system value="url"/>
      <value value="http://www.hl7.org/Special/committees/pher"/>
    </telecom>
  </contact>
  <description value="This profile describes the US Public Health CodeSystem."/>
  <jurisdiction>
    <coding>
      <system value="urn:iso:std:iso:3166"/>
      <code value="US"/>
      <display value="United States of America"/>
    </coding>
    <text value="United States of America"/>
  </jurisdiction>
  <fhirVersion value="4.0.1"/>
  <mapping>
    <identity value="rim"/>
    <uri value="http://hl7.org/v3"/>
    <name value="RIM Mapping"/>
  </mapping>
  <mapping>
    <identity value="workflow"/>
    <uri value="http://hl7.org/fhir/workflow"/>
    <name value="Workflow Pattern"/>
  </mapping>
  <mapping>
    <identity value="w5"/>
    <uri value="http://hl7.org/fhir/fivews"/>
    <name value="FiveWs Pattern Mapping"/>
  </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="CodeSystem"/>
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/CodeSystem"/>
  <derivation value="constraint"/>
  <snapshot>
    <element id="CodeSystem">
      <path value="CodeSystem"/>
      <short value="US Public Health CodeSystem"/>
      <definition
                  value="The CodeSystem resource is used to declare the existence of and describe a code system or code system supplement and its key properties, and optionally define a part or all of its content."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="CodeSystem"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <constraint>
        <key value="csd-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.matches(&#39;[A-Z]([A-Za-z0-9_]){0,254}&#39;)"/>
        <xpath
               value="not(exists(f:name/@value)) or matches(f:name/@value, &#39;[A-Z]([A-Za-z0-9_]){0,254}&#39;)"/>
        <source value="http://hl7.org/fhir/StructureDefinition/CodeSystem"/>
      </constraint>
      <constraint>
        <key value="csd-1"/>
        <severity value="error"/>
        <human
               value="Within a code system definition, all the codes SHALL be unique"/>
        <expression
                    value="concept.code.combine($this.descendants().concept.code).isDistinct()"/>
        <xpath
               value="count(distinct-values(descendant::f:concept/f:code/@value))=count(descendant::f:concept)"/>
        <source value="http://hl7.org/fhir/StructureDefinition/CodeSystem"/>
      </constraint>
      <constraint>
        <key value="dom-2"/>
        <severity value="error"/>
        <human
               value="If the resource is contained in another resource, it SHALL NOT contain nested Resources"/>
        <expression value="contained.contained.empty()"/>
        <xpath value="not(parent::f:contained and f:contained)"/>
        <source value="http://hl7.org/fhir/StructureDefinition/DomainResource"/>
      </constraint>
      <constraint>
        <key value="dom-3"/>
        <severity value="error"/>
        <human
               value="If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource or SHALL refer to the containing resource"/>
        <expression
                    value="contained.where(((&#39;#&#39;+id in (%resource.descendants().reference | %resource.descendants().as(canonical) | %resource.descendants().as(uri) | %resource.descendants().as(url))) or descendants().where(reference = &#39;#&#39;).exists() or descendants().where(as(canonical) = &#39;#&#39;).exists() or descendants().where(as(canonical) = &#39;#&#39;).exists()).not()).trace(&#39;unmatched&#39;, id).empty()"/>
        <xpath
               value="not(exists(for $id in f:contained/*/f:id/@value return $contained[not(parent::*/descendant::f:reference/@value=concat(&#39;#&#39;, $contained/*/id/@value) or descendant::f:reference[@value=&#39;#&#39;])]))"/>
        <source value="http://hl7.org/fhir/StructureDefinition/DomainResource"/>
      </constraint>
      <constraint>
        <key value="dom-4"/>
        <severity value="error"/>
        <human
               value="If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated"/>
        <expression
                    value="contained.meta.versionId.empty() and contained.meta.lastUpdated.empty()"/>
        <xpath
               value="not(exists(f:contained/*/f:meta/f:versionId)) and not(exists(f:contained/*/f:meta/f:lastUpdated))"/>
        <source value="http://hl7.org/fhir/StructureDefinition/DomainResource"/>
      </constraint>
      <constraint>
        <key value="dom-5"/>
        <severity value="error"/>
        <human
               value="If a resource is contained in another resource, it SHALL NOT have a security label"/>
        <expression value="contained.meta.security.empty()"/>
        <xpath value="not(exists(f:contained/*/f:meta/f:security))"/>
        <source value="http://hl7.org/fhir/StructureDefinition/DomainResource"/>
      </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="When a resource has no narrative, only systems that fully understand the data can display the resource to a human safely. Including a human readable representation in the resource makes for a much more robust eco-system and cheaper handling of resources by intermediary systems. Some ecosystems restrict distribution of resources to only those systems that do fully understand the resources, and as a consequence implementers may believe that the narrative is superfluous. However experience shows that such eco-systems often open up to new participants over time."/>
        </extension>
        <key value="dom-6"/>
        <severity value="warning"/>
        <human value="A resource should have narrative for robust management"/>
        <expression value="text.`div`.exists()"/>
        <xpath value="exists(f:text/h:div)"/>
        <source value="http://hl7.org/fhir/StructureDefinition/DomainResource"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="Entity. Role, or Act"/>
      </mapping>
      <mapping>
        <identity value="rim"/>
        <map value="N/A"/>
      </mapping>
    </element>
    <element id="CodeSystem.id">
      <path value="CodeSystem.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="The only time that a resource does not have an id is when it is being submitted to the server using a create operation."/>
      <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="string"/>
        </extension>
        <code value="http://hl7.org/fhirpath/System.String"/>
      </type>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="CodeSystem.meta">
      <path value="CodeSystem.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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="CodeSystem.implicitRules">
      <path value="CodeSystem.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 it&#39;s 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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <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 it&#39;s meaning or interpretation"/>
      <isSummary value="true"/>
    </element>
    <element id="CodeSystem.language">
      <path value="CodeSystem.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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <binding>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-maxValueSet">
          <valueCanonical value="http://hl7.org/fhir/ValueSet/all-languages"/>
        </extension>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="Language"/>
        </extension>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-isCommonBinding">
          <valueBoolean value="true"/>
        </extension>
        <strength value="preferred"/>
        <description value="A human language."/>
        <valueSet value="http://hl7.org/fhir/ValueSet/languages"/>
      </binding>
    </element>
    <element id="CodeSystem.text">
      <path value="CodeSystem.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 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>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="Act.text?"/>
      </mapping>
    </element>
    <element id="CodeSystem.contained">
      <path value="CodeSystem.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, and nor can they have their own independent transaction scope."/>
      <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>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="N/A"/>
      </mapping>
    </element>
    <element id="CodeSystem.extension">
      <path value="CodeSystem.extension"/>
      <short value="Additional content defined by implementations"/>
      <definition
                  value="May be used to represent additional information that is not part of the basic definition of the resource. To make the use of extensions safe and manageable, there is a strict set of governance  applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension."/>
      <comment
               value="There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions.  The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone."/>
      <alias value="extensions"/>
      <alias value="user content"/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <constraint>
        <key value="ext-1"/>
        <severity value="error"/>
        <human value="Must have either extensions or value[x], not both"/>
        <expression value="extension.exists() != value.exists()"/>
        <xpath
               value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/>
        <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="CodeSystem.modifierExtension">
      <path value="CodeSystem.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&#39;s descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer 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/R4/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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <constraint>
        <key value="ext-1"/>
        <severity value="error"/>
        <human value="Must have either extensions or value[x], not both"/>
        <expression value="extension.exists() != value.exists()"/>
        <xpath
               value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/>
        <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 resource that contains them"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="N/A"/>
      </mapping>
    </element>
    <element id="CodeSystem.url">
      <path value="CodeSystem.url"/>
      <short
             value="Canonical identifier for this code system, represented as a URI (globally unique) (Coding.system)"/>
      <definition
                  value="An absolute URI that is used to identify this code system 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 at which an authoritative instance of this code system is (or will be) published. This URL can be the target of a canonical reference. It SHALL remain the same when the code system is stored on different servers. This is used in [Coding](http://hl7.org/fhir/R4/datatypes.html#Coding).system."/>
      <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/R4/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/R4/resource.html#meta) element to indicate where the current master source of the resource can be found."/>
      <requirements
                    value="Allows the code system to be referenced by a single globally unique identifier."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.url"/>
        <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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.url"/>
      </mapping>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.identifier"/>
      </mapping>
    </element>
    <element id="CodeSystem.identifier">
      <path value="CodeSystem.identifier"/>
      <short
             value="Additional identifier for the code system (business identifier)"/>
      <definition
                  value="A formal identifier that is used to identify this code system 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 code system outside of FHIR, where it is not possible to use the logical URI.  Note that HL7 defines at least three identifiers for many of its code systems - the FHIR canonical URL, the OID and the V2 Table 0396 mnemonic code."/>
      <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="CodeSystem.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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.identifier"/>
      </mapping>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.identifier"/>
      </mapping>
      <mapping>
        <identity value="objimpl"/>
        <map value="no-gen-base"/>
      </mapping>
    </element>
    <element id="CodeSystem.version">
      <path value="CodeSystem.version"/>
      <short value="Business version of the code system (Coding.version)"/>
      <definition
                  value="The identifier that is used to identify this version of the code system when it is referenced in a specification, model, design or instance. This is an arbitrary value managed by the code system author and is not expected to be globally unique. For example, it might be a timestamp (e.g. yyyymmdd) if a managed version is not available. There is also no expectation that versions can be placed in a lexicographical sequence. This is used in [Coding](http://hl7.org/fhir/R4/datatypes.html#Coding).version."/>
      <comment
               value="There may be different code system 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 code system with the format [url]|[version]."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.version"/>
      </mapping>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.version"/>
      </mapping>
    </element>
    <element id="CodeSystem.name">
      <path value="CodeSystem.name"/>
      <short value="Name for this code system (computer friendly)"/>
      <definition
                  value="A natural language name identifying the code system. 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."/>
      <requirements value="Support human navigation and code generation."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.name"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="string"/>
      </type>
      <condition value="inv-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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="CodeSystem.title">
      <path value="CodeSystem.title"/>
      <short value="Name for this code system (human friendly)"/>
      <definition
                  value="A short, descriptive, user-friendly title for the code system."/>
      <comment
               value="This name does not need to be machine-processing friendly and may contain punctuation, white-space, etc."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.title"/>
      </mapping>
    </element>
    <element id="CodeSystem.status">
      <path value="CodeSystem.status"/>
      <short value="draft | active | retired | unknown"/>
      <definition
                  value="The date (and optionally time) when the code system resource was created or revised."/>
      <comment
               value="Allows filtering of code systems that are appropriate for use versus not."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <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>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-isCommonBinding">
          <valueBoolean value="true"/>
        </extension>
        <strength value="required"/>
        <description value="The lifecycle status of an artifact."/>
        <valueSet value="http://hl7.org/fhir/ValueSet/publication-status|4.0.1"/>
      </binding>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.status"/>
      </mapping>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.status"/>
      </mapping>
    </element>
    <element id="CodeSystem.experimental">
      <path value="CodeSystem.experimental"/>
      <short value="For testing purposes, not real usage"/>
      <definition
                  value="A Boolean value to indicate that this code system is authored for testing purposes (or education/evaluation/marketing) and is not intended to be used for genuine usage."/>
      <comment
               value="Allows filtering of code systems 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 code system."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.experimental"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="boolean"/>
      </type>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.experimental"/>
      </mapping>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.class"/>
      </mapping>
    </element>
    <element id="CodeSystem.date">
      <path value="CodeSystem.date"/>
      <short value="Date last changed"/>
      <definition
                  value="The date  (and optionally time) when the code system was published. 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 code system changes."/>
      <comment
               value="Note that this is not the same as the resource last-modified-date, since the resource may be a secondary representation of the code system. Additional specific dates may be added as extensions or be found by consulting Provenances associated with past versions of the resource."/>
      <alias value="Revision Date"/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.date"/>
      </mapping>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.recorded"/>
      </mapping>
    </element>
    <element id="CodeSystem.publisher">
      <path value="CodeSystem.publisher"/>
      <short value="Name of the publisher (organization or individual)"/>
      <definition
                  value="The name of the organization or individual that published the code system."/>
      <comment
               value="Usually an organization but may be an individual. The publisher (or steward) of the code system is the organization or individual primarily responsible for the maintenance and upkeep of the code system. 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 code system. This item SHOULD be populated unless the information is available from context."/>
      <requirements
                    value="Helps establish the &quot;authority/credibility&quot; of the code system.  May also allow for contact."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.publisher"/>
      </mapping>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.witness"/>
      </mapping>
    </element>
    <element id="CodeSystem.contact">
      <path value="CodeSystem.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."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="CodeSystem.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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.contact"/>
      </mapping>
    </element>
    <element id="CodeSystem.description">
      <path value="CodeSystem.description"/>
      <short value="Natural language description of the code system"/>
      <definition
                  value="A free text natural language description of the code system from a consumer&#39;s perspective."/>
      <comment
               value="This description can be used to capture details such as why the code system was built, comments about misuse, instructions for clinical use and interpretation, literature references, examples from the paper world, etc. It is not a rendering of the code system as conveyed in the &#39;text&#39; field of the resource itself. This item SHOULD be populated unless the information is available from context (e.g. the language of the code system is presumed to be the predominant language in the place the code system was created)."/>
      <alias value="Scope"/>
      <alias value="Purpose"/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.description"/>
      </mapping>
      <mapping>
        <identity value="rim"/>
        <map value="N/A"/>
      </mapping>
    </element>
    <element id="CodeSystem.useContext">
      <extension
                 url="http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status">
        <valueCode value="trial-use"/>
      </extension>
      <path value="CodeSystem.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 code system 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="CodeSystem.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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.useContext"/>
      </mapping>
    </element>
    <element id="CodeSystem.jurisdiction">
      <path value="CodeSystem.jurisdiction"/>
      <short value="Intended jurisdiction for code system (if applicable)"/>
      <definition
                  value="A legal or geographic region in which the code system is intended to be used."/>
      <comment
               value="It may be possible for the code system to be used in jurisdictions other than those for which it was originally designed or intended."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="CodeSystem.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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <binding>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="Jurisdiction"/>
        </extension>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-isCommonBinding">
          <valueBoolean value="true"/>
        </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>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.jurisdiction"/>
      </mapping>
    </element>
    <element id="CodeSystem.purpose">
      <path value="CodeSystem.purpose"/>
      <short value="Why this code system is defined"/>
      <definition
                  value="Explanation of why this code system is needed and why it has been designed as it has."/>
      <comment
               value="This element does not describe the usage of the code system. Instead, it provides traceability of &#39;&#39;why&#39;&#39; the resource is either needed or &#39;&#39;why&#39;&#39; it is defined as it is.  This may be used to point to source materials or specifications that drove the structure of this code system."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.purpose"/>
      </mapping>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.why[x]"/>
      </mapping>
      <mapping>
        <identity value="objimpl"/>
        <map value="no-gen-base"/>
      </mapping>
    </element>
    <element id="CodeSystem.copyright">
      <path value="CodeSystem.copyright"/>
      <short value="Use and/or publishing restrictions"/>
      <definition
                  value="A copyright statement relating to the code system and/or its contents. Copyright statements are generally legal restrictions on the use and publishing of the code system."/>
      <comment
               value="... Sometimes, the copyright differs between the code system and the codes that are included. The copyright statement should clearly differentiate between these when required."/>
      <requirements
                    value="Consumers must be able to determine any legal restrictions on the use of the code system and/or its content."/>
      <alias value="License"/>
      <alias value="Restrictions"/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.copyright"/>
      </mapping>
      <mapping>
        <identity value="objimpl"/>
        <map value="no-gen-base"/>
      </mapping>
    </element>
    <element id="CodeSystem.caseSensitive">
      <path value="CodeSystem.caseSensitive"/>
      <short value="If code comparison is case sensitive"/>
      <definition
                  value="If code comparison is case sensitive when codes within this system are compared to each other."/>
      <comment
               value="If this value is missing, then it is not specified whether a code system is case sensitive or not. When the rule is not known, Postel&#39;s law should be followed: produce codes with the correct case, and accept codes in any case. This element is primarily provided to support validation software."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.caseSensitive"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="boolean"/>
      </type>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="CodeSystem.valueSet">
      <path value="CodeSystem.valueSet"/>
      <short
             value="Canonical reference to the value set with entire code system"/>
      <definition
                  value="Canonical reference to the value set that contains the entire code system."/>
      <comment
               value="The definition of the value set SHALL include all codes from this code system and only codes from this code system, and it SHALL be immutable."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.valueSet"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="canonical"/>
        <targetProfile value="http://hl7.org/fhir/StructureDefinition/ValueSet"/>
      </type>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="CodeSystem.hierarchyMeaning">
      <path value="CodeSystem.hierarchyMeaning"/>
      <short value="grouped-by | is-a | part-of | classified-with"/>
      <definition
                  value="The meaning of the hierarchy of concepts as represented in this resource."/>
      <comment
               value="Note that other representations might have a different hierarchy or none at all, and represent the information using properties."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.hierarchyMeaning"/>
        <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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <binding>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="CodeSystemHierarchyMeaning"/>
        </extension>
        <strength value="required"/>
        <description
                     value="The meaning of the hierarchy of concepts in a code system."/>
        <valueSet
                  value="http://hl7.org/fhir/ValueSet/codesystem-hierarchy-meaning|4.0.1"/>
      </binding>
    </element>
    <element id="CodeSystem.compositional">
      <path value="CodeSystem.compositional"/>
      <short value="If code system defines a compositional grammar"/>
      <definition
                  value="The code system defines a compositional (post-coordination) grammar."/>
      <comment
               value="Note that the code system resource does not define what the compositional grammar is, only whether or not there is one."/>
      <alias value="grammar"/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.compositional"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="boolean"/>
      </type>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="CodeSystem.versionNeeded">
      <path value="CodeSystem.versionNeeded"/>
      <short value="If definitions are not stable"/>
      <definition
                  value="This flag is used to signify that the code system does not commit to concept permanence across versions. If true, a version must be specified when referencing this code system."/>
      <comment
               value="Best practice is that code systems do not redefine concepts, or that if concepts are redefined, a new code system definition is created. But this is not always possible, so some code systems may be defined as &#39;versionNeeded&#39;.

Most code systems occasionally refine the displays defined for concepts between versions. Contexts in which the concept display values are validated may require that the version be specified for some code systems irrespective of the value of this property."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.versionNeeded"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="boolean"/>
      </type>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="CodeSystem.content">
      <path value="CodeSystem.content"/>
      <short value="not-present | example | fragment | complete | supplement"/>
      <definition
                  value="The extent of the content of the code system (the concepts and codes it defines) are represented in this resource instance."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.content"/>
        <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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <binding>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="CodeSystemContentMode"/>
        </extension>
        <strength value="required"/>
        <description
                     value="The extent of the content of the code system (the concepts and codes it defines) are represented in a code system resource."/>
        <valueSet
                  value="http://hl7.org/fhir/ValueSet/codesystem-content-mode|4.0.1"/>
      </binding>
    </element>
    <element id="CodeSystem.supplements">
      <path value="CodeSystem.supplements"/>
      <short
             value="Canonical URL of Code System this adds designations and properties to"/>
      <definition
                  value="The canonical URL of the code system that this code system supplement is adding designations and properties to."/>
      <comment
               value="The most common use of a code system supplement is to add additional language support."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.supplements"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="canonical"/>
        <targetProfile
                       value="http://hl7.org/fhir/StructureDefinition/CodeSystem"/>
      </type>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="CodeSystem.count">
      <path value="CodeSystem.count"/>
      <short value="Total concepts in the code system"/>
      <definition
                  value="The total number of concepts defined by the code system. Where the code system has a compositional grammar, the basis of this count is defined by the system steward."/>
      <comment
               value="The count of concepts defined in this resource cannot be more than this value but may be less for several reasons - see the content element."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.count"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="unsignedInt"/>
      </type>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="CodeSystem.filter">
      <path value="CodeSystem.filter"/>
      <short value="Filter that can be used in a value set"/>
      <definition
                  value="A filter that can be used in a value set compose statement when selecting concepts using a filter."/>
      <comment
               value="Note that filters defined in code systems usually require custom code on the part of any terminology engine that will make them available for use in value set filters. For this reason, they are generally only seen in high value published terminologies."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="CodeSystem.filter"/>
        <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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="CodeSystem.filter.id">
      <path value="CodeSystem.filter.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>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="n/a"/>
      </mapping>
    </element>
    <element id="CodeSystem.filter.extension">
      <path value="CodeSystem.filter.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 manageable, there is a strict set of governance  applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension."/>
      <comment
               value="There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions.  The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone."/>
      <alias value="extensions"/>
      <alias value="user content"/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="Element.extension"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="Extension"/>
      </type>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <constraint>
        <key value="ext-1"/>
        <severity value="error"/>
        <human value="Must have either extensions or value[x], not both"/>
        <expression value="extension.exists() != value.exists()"/>
        <xpath
               value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/>
        <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="CodeSystem.filter.modifierExtension">
      <path value="CodeSystem.filter.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&#39;s descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. 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/R4/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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <constraint>
        <key value="ext-1"/>
        <severity value="error"/>
        <human value="Must have either extensions or value[x], not both"/>
        <expression value="extension.exists() != value.exists()"/>
        <xpath
               value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/>
        <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="CodeSystem.filter.code">
      <path value="CodeSystem.filter.code"/>
      <short value="Code that identifies the filter"/>
      <definition
                  value="The code that identifies this filter when it is used as a filter in [ValueSet](http://hl7.org/fhir/R4/valueset.html#).compose.include.filter."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.filter.code"/>
        <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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="CodeSystem.filter.description">
      <path value="CodeSystem.filter.description"/>
      <short value="How or why the filter is used"/>
      <definition value="A description of how or why the filter is used."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.filter.description"/>
        <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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="CodeSystem.filter.operator">
      <path value="CodeSystem.filter.operator"/>
      <short
             value="= | is-a | descendent-of | is-not-a | regex | in | not-in | generalizes | exists"/>
      <definition value="A list of operators that can be used with the filter."/>
      <min value="1"/>
      <max value="*"/>
      <base>
        <path value="CodeSystem.filter.operator"/>
        <min value="1"/>
        <max value="*"/>
      </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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <binding>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="FilterOperator"/>
        </extension>
        <strength value="required"/>
        <description
                     value="The kind of operation to perform as a part of a property based filter."/>
        <valueSet value="http://hl7.org/fhir/ValueSet/filter-operator|4.0.1"/>
      </binding>
    </element>
    <element id="CodeSystem.filter.value">
      <path value="CodeSystem.filter.value"/>
      <short value="What to use for the value"/>
      <definition
                  value="A description of what the value for the filter should be."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.filter.value"/>
        <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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="CodeSystem.property">
      <extension
                 url="http://hl7.org/fhir/StructureDefinition/structuredefinition-explicit-type-name">
        <valueString value="Property"/>
      </extension>
      <path value="CodeSystem.property"/>
      <short value="Additional information supplied about each concept"/>
      <definition
                  value="A property defines an additional slot through which additional information can be provided about a concept."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="CodeSystem.property"/>
        <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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <mustSupport value="true"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="CodeSystem.property.id">
      <path value="CodeSystem.property.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>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="n/a"/>
      </mapping>
    </element>
    <element id="CodeSystem.property.extension">
      <path value="CodeSystem.property.extension"/>
      <slicing>
        <discriminator>
          <type value="value"/>
          <path value="url"/>
        </discriminator>
        <ordered value="false"/>
        <rules value="open"/>
      </slicing>
      <short value="Extension"/>
      <definition value="An Extension"/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="Element.extension"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="Extension"/>
      </type>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <constraint>
        <key value="ext-1"/>
        <severity value="error"/>
        <human value="Must have either extensions or value[x], not both"/>
        <expression value="extension.exists() != value.exists()"/>
        <xpath
               value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
    <element id="CodeSystem.property.extension:binding">
      <path value="CodeSystem.property.extension"/>
      <sliceName value="binding"/>
      <short value="What values are allowed"/>
      <definition
                  value="A reference to a CodeSystem or ValueSet that establishes the allowable values for a code system property."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="Element.extension"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="Extension"/>
        <profile
                 value="http://hl7.org/fhir/us/ecr/StructureDefinition/us-ph-codesystem-property-binding-extension"/>
      </type>
      <condition value="ele-1"/>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <constraint>
        <key value="ext-1"/>
        <severity value="error"/>
        <human value="Must have either extensions or value[x], not both"/>
        <expression value="extension.exists() != value.exists()"/>
        <xpath
               value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &#39;value&#39;)])"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/>
      </constraint>
      <mustSupport value="true"/>
      <isModifier value="false"/>
    </element>
    <element id="CodeSystem.property.modifierExtension">
      <path value="CodeSystem.property.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&#39;s descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. 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/R4/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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <constraint>
        <key value="ext-1"/>
        <severity value="error"/>
        <human value="Must have either extensions or value[x], not both"/>
        <expression value="extension.exists() != value.exists()"/>
        <xpath
               value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/>
        <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="CodeSystem.property.code">
      <path value="CodeSystem.property.code"/>
      <short
             value="Identifies the property on the concepts, and when referred to in operations"/>
      <definition
                  value="A code that is used to identify the property. The code is used internally (in CodeSystem.concept.property.code) and also externally, such as in property filters."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.property.code"/>
        <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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="CodeSystem.property.uri">
      <path value="CodeSystem.property.uri"/>
      <short value="Formal identifier for the property"/>
      <definition
                  value="Reference to the formal meaning of the property. One possible source of meaning is the [Concept Properties](codesystem-concept-properties.html) code system."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.property.uri"/>
        <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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="CodeSystem.property.description">
      <path value="CodeSystem.property.description"/>
      <short value="Why the property is defined, and/or what it conveys"/>
      <definition
                  value="A description of the property- why it is defined, and how its value might be used."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.property.description"/>
        <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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="CodeSystem.property.type">
      <path value="CodeSystem.property.type"/>
      <short
             value="code | Coding | string | integer | boolean | dateTime | decimal"/>
      <definition
                  value="The type of the property value. Properties of type &quot;code&quot; contain a code defined by the code system (e.g. a reference to another defined concept)."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.property.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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <binding>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="PropertyType"/>
        </extension>
        <strength value="required"/>
        <description value="The type of a property value."/>
        <valueSet
                  value="http://hl7.org/fhir/ValueSet/concept-property-type|4.0.1"/>
      </binding>
    </element>
    <element id="CodeSystem.concept">
      <extension
                 url="http://hl7.org/fhir/StructureDefinition/structuredefinition-explicit-type-name">
        <valueString value="ConceptDefinition"/>
      </extension>
      <path value="CodeSystem.concept"/>
      <short value="Concepts in the code system"/>
      <definition
                  value="Concepts that are in the code system. The concept definitions are inherently hierarchical, but the definitions must be consulted to determine what the meanings of the hierarchical relationships are."/>
      <comment
               value="If this is empty, it means that the code system resource does not represent the content of the code system."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="CodeSystem.concept"/>
        <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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
    <element id="CodeSystem.concept.id">
      <path value="CodeSystem.concept.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>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="n/a"/>
      </mapping>
    </element>
    <element id="CodeSystem.concept.extension">
      <path value="CodeSystem.concept.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 manageable, there is a strict set of governance  applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension."/>
      <comment
               value="There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions.  The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone."/>
      <alias value="extensions"/>
      <alias value="user content"/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="Element.extension"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="Extension"/>
      </type>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <constraint>
        <key value="ext-1"/>
        <severity value="error"/>
        <human value="Must have either extensions or value[x], not both"/>
        <expression value="extension.exists() != value.exists()"/>
        <xpath
               value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/>
        <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="CodeSystem.concept.modifierExtension">
      <path value="CodeSystem.concept.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&#39;s descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. 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/R4/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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <constraint>
        <key value="ext-1"/>
        <severity value="error"/>
        <human value="Must have either extensions or value[x], not both"/>
        <expression value="extension.exists() != value.exists()"/>
        <xpath
               value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/>
        <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="CodeSystem.concept.code">
      <path value="CodeSystem.concept.code"/>
      <short value="Code that identifies concept"/>
      <definition
                  value="A code - a text symbol - that uniquely identifies the concept within the code system."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.concept.code"/>
        <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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
    <element id="CodeSystem.concept.display">
      <path value="CodeSystem.concept.display"/>
      <short value="Text to display to the user"/>
      <definition
                  value="A human readable string that is the recommended default way to present this concept to a user."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.concept.display"/>
        <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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
    <element id="CodeSystem.concept.definition">
      <path value="CodeSystem.concept.definition"/>
      <short value="Formal definition"/>
      <definition
                  value="The formal definition of the concept. The code system resource does not make formal definitions required, because of the prevalence of legacy systems. However, they are highly recommended, as without them there is no formal meaning associated with the concept."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.concept.definition"/>
        <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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
    <element id="CodeSystem.concept.designation">
      <path value="CodeSystem.concept.designation"/>
      <short value="Additional representations for the concept"/>
      <definition
                  value="Additional representations for the concept - other languages, aliases, specialized purposes, used for particular purposes, etc."/>
      <comment
               value="Concepts have both a ```display``` and an array of ```designation```. The display is equivalent to a special designation with an implied ```designation.use``` of &quot;primary code&quot; and a language equal to the [Resource Language](http://hl7.org/fhir/R4/resource.html#language)."/>
      <requirements
                    value="Many concept definition systems support multiple representations, in multiple languages, and for multiple purposes."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="CodeSystem.concept.designation"/>
        <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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
    <element id="CodeSystem.concept.designation.id">
      <path value="CodeSystem.concept.designation.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>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="n/a"/>
      </mapping>
    </element>
    <element id="CodeSystem.concept.designation.extension">
      <path value="CodeSystem.concept.designation.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 manageable, there is a strict set of governance  applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension."/>
      <comment
               value="There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions.  The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone."/>
      <alias value="extensions"/>
      <alias value="user content"/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="Element.extension"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="Extension"/>
      </type>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <constraint>
        <key value="ext-1"/>
        <severity value="error"/>
        <human value="Must have either extensions or value[x], not both"/>
        <expression value="extension.exists() != value.exists()"/>
        <xpath
               value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/>
        <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="CodeSystem.concept.designation.modifierExtension">
      <path value="CodeSystem.concept.designation.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&#39;s descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. 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/R4/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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <constraint>
        <key value="ext-1"/>
        <severity value="error"/>
        <human value="Must have either extensions or value[x], not both"/>
        <expression value="extension.exists() != value.exists()"/>
        <xpath
               value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/>
        <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="CodeSystem.concept.designation.language">
      <path value="CodeSystem.concept.designation.language"/>
      <short value="Human language of the designation"/>
      <definition value="The language this designation is defined for."/>
      <comment
               value="In the absence of a language, the resource language applies."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.concept.designation.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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <binding>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-maxValueSet">
          <valueCanonical value="http://hl7.org/fhir/ValueSet/all-languages"/>
        </extension>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="Language"/>
        </extension>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-isCommonBinding">
          <valueBoolean value="true"/>
        </extension>
        <strength value="preferred"/>
        <description value="A human language."/>
        <valueSet value="http://hl7.org/fhir/ValueSet/languages"/>
      </binding>
    </element>
    <element id="CodeSystem.concept.designation.use">
      <path value="CodeSystem.concept.designation.use"/>
      <short value="Details how this designation would be used"/>
      <definition
                  value="A code that details how this designation would be used."/>
      <comment
               value="If no use is provided, the designation can be assumed to be suitable for general display to a human user."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.concept.designation.use"/>
        <min value="0"/>
        <max value="1"/>
      </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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <binding>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="ConceptDesignationUse"/>
        </extension>
        <strength value="extensible"/>
        <description value="Details of how a designation would be used."/>
        <valueSet value="http://hl7.org/fhir/ValueSet/designation-use"/>
      </binding>
    </element>
    <element id="CodeSystem.concept.designation.value">
      <path value="CodeSystem.concept.designation.value"/>
      <short value="The text value for this designation"/>
      <definition value="The text value for this designation."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.concept.designation.value"/>
        <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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
    <element id="CodeSystem.concept.property">
      <extension
                 url="http://hl7.org/fhir/StructureDefinition/structuredefinition-explicit-type-name">
        <valueString value="ConceptProperty"/>
      </extension>
      <path value="CodeSystem.concept.property"/>
      <short value="Property value for the concept"/>
      <definition value="A property value for this concept."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="CodeSystem.concept.property"/>
        <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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
    <element id="CodeSystem.concept.property.id">
      <path value="CodeSystem.concept.property.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>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="n/a"/>
      </mapping>
    </element>
    <element id="CodeSystem.concept.property.extension">
      <path value="CodeSystem.concept.property.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 manageable, there is a strict set of governance  applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension."/>
      <comment
               value="There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions.  The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone."/>
      <alias value="extensions"/>
      <alias value="user content"/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="Element.extension"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="Extension"/>
      </type>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <constraint>
        <key value="ext-1"/>
        <severity value="error"/>
        <human value="Must have either extensions or value[x], not both"/>
        <expression value="extension.exists() != value.exists()"/>
        <xpath
               value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/>
        <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="CodeSystem.concept.property.modifierExtension">
      <path value="CodeSystem.concept.property.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&#39;s descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. 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/R4/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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <constraint>
        <key value="ext-1"/>
        <severity value="error"/>
        <human value="Must have either extensions or value[x], not both"/>
        <expression value="extension.exists() != value.exists()"/>
        <xpath
               value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/>
        <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="CodeSystem.concept.property.code">
      <path value="CodeSystem.concept.property.code"/>
      <short value="Reference to CodeSystem.property.code"/>
      <definition
                  value="A code that is a reference to CodeSystem.property.code."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.concept.property.code"/>
        <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())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
    <element id="CodeSystem.concept.property.value[x]">
      <path value="CodeSystem.concept.property.value[x]"/>
      <short value="Value of the property for this concept"/>
      <definition value="The value of this property."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="CodeSystem.concept.property.value[x]"/>
        <min value="1"/>
        <max value="1"/>
      </base>
      <type>
        <code value="code"/>
      </type>
      <type>
        <code value="Coding"/>
      </type>
      <type>
        <code value="string"/>
      </type>
      <type>
        <code value="integer"/>
      </type>
      <type>
        <code value="boolean"/>
      </type>
      <type>
        <code value="dateTime"/>
      </type>
      <type>
        <code value="decimal"/>
      </type>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
    <element id="CodeSystem.concept.concept">
      <path value="CodeSystem.concept.concept"/>
      <short value="Child Concepts (is-a/contains/categorizes)"/>
      <definition
                  value="Defines children of a concept to produce a hierarchy of concepts. The nature of the relationships is variable (is-a/contains/categorizes) - see hierarchyMeaning."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="CodeSystem.concept.concept"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <contentReference
                        value="http://hl7.org/fhir/StructureDefinition/CodeSystem#CodeSystem.concept"/>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <xpath value="@value|f:*|h:div"/>
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
  </snapshot>
  <differential>
    <element id="CodeSystem">
      <path value="CodeSystem"/>
      <short value="US Public Health CodeSystem"/>
    </element>
    <element id="CodeSystem.property">
      <path value="CodeSystem.property"/>
      <mustSupport value="true"/>
    </element>
    <element id="CodeSystem.property.extension:binding">
      <path value="CodeSystem.property.extension"/>
      <sliceName value="binding"/>
      <short value="What values are allowed"/>
      <definition
                  value="A reference to a CodeSystem or ValueSet that establishes the allowable values for a code system property."/>
      <min value="0"/>
      <max value="1"/>
      <type>
        <code value="Extension"/>
        <profile
                 value="http://hl7.org/fhir/us/ecr/StructureDefinition/us-ph-codesystem-property-binding-extension"/>
      </type>
      <mustSupport value="true"/>
    </element>
  </differential>
</StructureDefinition>