Release 5

This page is part of the FHIR Specification (v5.0.0: R5 - STU). This is the current published version in it's permanent home (it will always be available at this URL). For a full list of available versions, see the Directory of published versions . Page versions: R5 R4B R4 R3 R2

Example StructureDefinition/Meta (XML)

Modeling and Methodology Work GroupMaturity Level: N/AStandards Status: Informative

Raw XML (canonical form + also see XML Format Specification)

StructureDefinition for Meta

<?xml version="1.0" encoding="UTF-8"?>

<StructureDefinition xmlns="http://hl7.org/fhir">
  <id value="Meta"/> 
  <text> 
    <status value="generated"/> 
    <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 class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">
            <a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="The logical name of the element">Name</a> 
          </th> 
          <th class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">
            <a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Information about the use of the element">Flags</a> 
          </th> 
          <th class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">
            <a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Minimum and Maximum # of times the the element can appear in the instance">Card.</a> 
          </th> 
          <th class="hierarchy" style="width: 100px">
            <a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Reference to the type of the element">Type</a> 
          </th> 
          <th class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">
            <a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Additional information about the element">Description &amp; Constraints</a> 
            <span style="float: right">
              <a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Legend for this format">
                <img alt="doco" src="data:(snipped in html view)" style="background-color: inherit"/> 
              </a> 
            </span> 
          </th> 
        </tr> 
        <tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color:
         white">
          <td class="hierarchy" 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(data:image/png;bas
          e64,iVBORw0KGgoAAAANSUhEUgAAAyAAAAACCAYAAACg/LjIAAAAJUlEQVR4Xu3IIQEAAAgDsHd9/w4EQIOamFnaBgAA4M
          MKAACAKwNp30CqZFfFmwAAAABJRU5ErkJggg==)">
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: white; background-color: inherit" title="Element"/>  
            <a href="resource-definitions.html#Meta" title="Meta : The metadata about a resource. This is content in the resource that is maintained
             by the infrastructure. Changes to the content might not always be associated with
             version changes to the resource.">Meta</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">
            <a href="elementdefinition-definitions.html#ElementDefinition.isSummary" style="padding-left: 3px; padding-right: 3px; color: black; null" title="This element is included in summaries">Σ</a> 
            <a href="versions.html#std-process" style="padding-left: 3px; padding-right: 3px; border: 1px grey solid; font-weight: bold;
             color: black; background-color: #e6ffe6" title="Standards Status = Normative">N</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px"/> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">
            <a href="types.html#Element">Element</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">Metadata about a resource
            <br/>  
            <br/>  Elements defined in Ancestors: 
            <a href="types.html#Element" title="Unique id for the element within a resource (for internal references). This may
             be any string value that does not contain spaces.">id</a> , 
            <a href="types.html#Element" title="May be used to represent additional information that is not part of the basic definition
             of the element. To make the use of extensions safe and managable, there is a strict
             set of governance applied to the definition and use of extensions. Though any implementer
             can define an extension, there is a set of requirements that SHALL be met as part
             of the definition of the extension.">extension</a> 
          </td> 
        </tr> 

        <tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color:
         #F7F7F7">
          <td class="hierarchy" 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(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAyAAAAACCAYAAACg/LjIAAAALUlEQVR4Xu3IoREAIAw
          EwfT6/ddA0GBAxO3NrLlKUj9263wAAAAvrgEAADClAVWFQIBRHMicAAAAAElFTkSuQmCC)">
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: #F7F7F7; background-color: inherit" title="Primitive Data Type"/>  
            <a href="resource-definitions.html#Meta.versionId" title="Meta.versionId : The version specific identifier, as it appears in the version
             portion of the URL. This value changes when the resource is created, updated, or
             deleted.">versionId</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px
           #F0F0F0 solid; padding:0px 4px 0px 4px">
            <a href="elementdefinition-definitions.html#ElementDefinition.isSummary" style="padding-left: 3px; padding-right: 3px; color: black; null" title="This element is included in summaries">Σ</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px
           #F0F0F0 solid; padding:0px 4px 0px 4px">0..1</td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px
           #F0F0F0 solid; padding:0px 4px 0px 4px">
            <a href="datatypes.html#id">id</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px
           #F0F0F0 solid; padding:0px 4px 0px 4px">Version specific identifier
            <br/>  
          </td> 
        </tr> 

        <tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color:
         white">
          <td class="hierarchy" 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(data:image/png;bas
          e64,iVBORw0KGgoAAAANSUhEUgAAAyAAAAACCAYAAACg/LjIAAAALUlEQVR4Xu3IoREAIAwEwfT6/ddA0GBAxO3NrLlKUj
          9263wAAAAvrgEAADClAVWFQIBRHMicAAAAAElFTkSuQmCC)">
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: white; background-color: inherit" title="Primitive Data Type"/>  
            <a href="resource-definitions.html#Meta.lastUpdated" title="Meta.lastUpdated : When the resource last changed - e.g. when the version changed.">lastUpdated</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">
            <a href="elementdefinition-definitions.html#ElementDefinition.isSummary" style="padding-left: 3px; padding-right: 3px; color: black; null" title="This element is included in summaries">Σ</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">0..1</td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">
            <a href="datatypes.html#instant">instant</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">When the resource version last changed
            <br/>  
          </td> 
        </tr> 

        <tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color:
         #F7F7F7">
          <td class="hierarchy" 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(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAyAAAAACCAYAAACg/LjIAAAALUlEQVR4Xu3IoREAIAw
          EwfT6/ddA0GBAxO3NrLlKUj9263wAAAAvrgEAADClAVWFQIBRHMicAAAAAElFTkSuQmCC)">
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: #F7F7F7; background-color: inherit" title="Primitive Data Type"/>  
            <a href="resource-definitions.html#Meta.source" title="Meta.source : A uri that identifies the source system of the resource. This provides
             a minimal amount of [[[Provenance]]] information that can be used to track or differentiate
             the source of information in the resource. The source may identify another FHIR
             server, document, message, database, etc.">source</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px
           #F0F0F0 solid; padding:0px 4px 0px 4px">
            <a href="elementdefinition-definitions.html#ElementDefinition.isSummary" style="padding-left: 3px; padding-right: 3px; color: black; null" title="This element is included in summaries">Σ</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px
           #F0F0F0 solid; padding:0px 4px 0px 4px">0..1</td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px
           #F0F0F0 solid; padding:0px 4px 0px 4px">
            <a href="datatypes.html#uri">uri</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px
           #F0F0F0 solid; padding:0px 4px 0px 4px">Identifies where the resource comes from
            <br/>  
          </td> 
        </tr> 

        <tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color:
         white">
          <td class="hierarchy" 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(data:image/png;bas
          e64,iVBORw0KGgoAAAANSUhEUgAAAyAAAAACCAYAAACg/LjIAAAALUlEQVR4Xu3IoREAIAwEwfT6/ddA0GBAxO3NrLlKUj
          9263wAAAAvrgEAADClAVWFQIBRHMicAAAAAElFTkSuQmCC)">
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: white; background-color: inherit" title="Reference to another Resource"/>  
            <a href="resource-definitions.html#Meta.profile" title="Meta.profile : A list of profiles (references to [[[StructureDefinition]]] resources)
             that this resource claims to conform to. The URL is a reference to [[[StructureDefinition.url
            ]]].">profile</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">
            <a href="elementdefinition-definitions.html#ElementDefinition.isSummary" style="padding-left: 3px; padding-right: 3px; color: black; null" title="This element is included in summaries">Σ</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">0..*</td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">
            <a href="datatypes.html#canonical">canonical</a> (
            <a href="structuredefinition.html">StructureDefinition</a> )
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">Profiles this resource claims to conform to
            <br/>  
            <br/>  
          </td> 
        </tr> 

        <tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color:
         #F7F7F7">
          <td class="hierarchy" 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(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAyAAAAACCAYAAACg/LjIAAAALUlEQVR4Xu3IoREAIAw
          EwfT6/ddA0GBAxO3NrLlKUj9263wAAAAvrgEAADClAVWFQIBRHMicAAAAAElFTkSuQmCC)">
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: #F7F7F7; background-color: inherit" title="Data Type"/>  
            <a href="resource-definitions.html#Meta.security" title="Meta.security : Security labels applied to this resource. These tags connect specific
             resources to the overall security policy and infrastructure.">security</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px
           #F0F0F0 solid; padding:0px 4px 0px 4px">
            <a href="elementdefinition-definitions.html#ElementDefinition.isSummary" style="padding-left: 3px; padding-right: 3px; color: black; null" title="This element is included in summaries">Σ</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px
           #F0F0F0 solid; padding:0px 4px 0px 4px">0..*</td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px
           #F0F0F0 solid; padding:0px 4px 0px 4px">
            <a href="datatypes.html#Coding">Coding</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px
           #F0F0F0 solid; padding:0px 4px 0px 4px">Security Labels applied to this resource
            <br/>  Binding: 
            <a href="valueset-security-labels.html" title="Security Labels from the Healthcare Privacy and Security Classification System.">All Security Labels</a>  (
            <a href="terminologies.html#extensible" title="To be conformant, the concept in this element SHALL be from the specified value
             set if any of the codes within the value set can apply to the concept being communicated.
              If the value set does not cover the concept (based on human review), alternate
             codings (or, data type allowing, text) may be included instead.">Extensible</a> )
            <br/>  
            <br/>  
          </td> 
        </tr> 

        <tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color:
         white">
          <td class="hierarchy" 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(data:image/png;bas
          e64,iVBORw0KGgoAAAANSUhEUgAAAyAAAAACCAYAAACg/LjIAAAAJUlEQVR4Xu3IIQEAAAgDsHd9/w4EQIOamFnaBgAA4M
          MKAACAKwNp30CqZFfFmwAAAABJRU5ErkJggg==)">
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: white; background-color: inherit" title="Data Type"/>  
            <a href="resource-definitions.html#Meta.tag" title="Meta.tag : Tags applied to this resource. Tags are intended to be used to identify
             and relate resources to process and workflow, and applications are not required
             to consider the tags when interpreting the meaning of a resource.">tag</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">
            <a href="elementdefinition-definitions.html#ElementDefinition.isSummary" style="padding-left: 3px; padding-right: 3px; color: black; null" title="This element is included in summaries">Σ</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">0..*</td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">
            <a href="datatypes.html#Coding">Coding</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">Tags applied to this resource
            <br/>  Binding: 
            <a href="valueset-common-tags.html" title="Codes that represent various types of tags, commonly workflow-related; e.g. &quot;Needs
             review by Dr. Jones&quot;.">Common Tags</a>  (
            <a href="terminologies.html#example" title="Instances are not expected or even encouraged to draw from the specified value
             set.  The value set merely provides examples of the types of concepts intended
             to be included.">Example</a> )
            <br/>  
            <br/>  
          </td> 
        </tr> 

        <tr> 
          <td class="hierarchy" colspan="5">
            <br/>  
            <a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Legend for this format">
              <img alt="doco" src="data:(snipped in html view)" style="background-color: inherit"/>  Documentation for this format
            </a> 
          </td> 
        </tr> 
      </table> 
    </div> 
  </text> 
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status">
    <valueCode value="normative"/> 
  </extension> 
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-normative-version">
    <valueCode value="4.0.0"/> 
  </extension> 
  <url value="http://hl7.org/fhir/StructureDefinition/Meta"/> 
  <version value="5.0.0"/> 
  <name value="Meta"/> 
  <status value="active"/> 
  <experimental value="false"/> 
  <date value="2023-03-26T15:21:02+11:00"/> 
  <publisher value="HL7 FHIR Standard"/> 
  <contact> 
    <telecom> 
      <system value="url"/> 
      <value value="http://hl7.org/fhir"/> 
    </telecom> 
  </contact> 
  <description value="Meta Type: The metadata about a resource. This is content in the resource that
   is maintained by the infrastructure. Changes to the content might not always be
   associated with version changes to the resource."/> 
  <jurisdiction> 
    <coding> 
      <system value="http://unstats.un.org/unsd/methods/m49/m49.htm"/> 
      <code value="001"/> 
      <display value="World"/> 
    </coding> 
  </jurisdiction> 
  <fhirVersion value="5.0.0"/> 
  <mapping> 
    <identity value="rim"/> 
    <uri value="http://hl7.org/v3"/> 
    <name value="RIM Mapping"/> 
  </mapping> 
  <kind value="complex-type"/> 
  <abstract value="false"/> 
  <type value="Meta"/> 
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/DataType"/> 
  <derivation value="specialization"/> 
  <snapshot> 
    <element id="Meta">
      <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status">
        <valueCode value="normative"/> 
      </extension> 
      <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-normative-version">
        <valueCode value="4.0.0"/> 
      </extension> 
      <path value="Meta"/> 
      <short value="Metadata about a resource"/> 
      <definition value="The metadata about a resource. This is content in the resource 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="*"/> 
      <base> 
        <path value="Meta"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="n/a,N/A"/> 
      </mapping> 
    </element> 
    <element id="Meta.id">
      <path value="Meta.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> 
      <!--  Note: special primitive values have a FHIRPath system type. e.g. this is compiler
       magic (j)  -->
      <type> 
        <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
          <valueUrl value="id"/> 
        </extension> 
        <code value="http://hl7.org/fhirpath/System.String"/> 
      </type> 
      <condition value="ele-1"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="n/a"/> 
      </mapping> 
    </element> 
    <element id="Meta.extension">
      <path value="Meta.extension"/> 
      <slicing> 
        <discriminator> 
          <type value="value"/> 
          <path value="url"/> 
        </discriminator> 
        <description value="Extensions are always sliced by (at least) url"/> 
        <rules value="open"/> 
      </slicing> 
      <short value="Additional content defined by implementations"/> 
      <definition value="May be used to represent additional information that is not part of the basic definition
       of the element. To make the use of extensions safe and managable, there is a strict
       set of governance applied to the definition and use of extensions. Though any implementer
       can define an extension, there is a set of requirements that SHALL be met as part
       of the definition of the extension."/> 
      <comment value="There can be no stigma associated with the use of extensions by any application,
       project, or standard - regardless of the institution or jurisdiction that uses
       or defines the extensions.  The use of extensions is what allows the FHIR specification
       to retain a core level of simplicity for everyone."/> 
      <alias value="extensions"/> 
      <alias value="user content"/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="Element.extension"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Extension"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <constraint> 
        <key value="ext-1"/> 
        <severity value="error"/> 
        <human value="Must have either extensions or value[x], not both"/> 
        <expression value="extension.exists() != value.exists()"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="n/a"/> 
      </mapping> 
    </element> 
    <element id="Meta.versionId">
      <path value="Meta.versionId"/> 
      <short value="Version specific identifier"/> 
      <definition value="The version specific identifier, as it appears in the version portion of the URL.
       This value changes when the resource is created, updated, or deleted."/> 
      <comment value="The server assigns this value, and ignores what the client specifies, except in
       the case that the server is imposing version integrity on updates/deletes."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Meta.versionId"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="id"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="Meta.lastUpdated">
      <path value="Meta.lastUpdated"/> 
      <short value="When the resource version last changed"/> 
      <definition value="When the resource last changed - e.g. when the version changed."/> 
      <comment value="This element is generally omitted in instances submitted in a PUT or POST. Instead,
       it is populated in the response instance and when retrieving information using
       a GET. The server / resource manager sets this value; what a client provides is
       irrelevant. This is equivalent to the HTTP Last-Modified and SHOULD have the same
       value on a [read](http.html#read) interaction."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Meta.lastUpdated"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="instant"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="Meta.source">
      <path value="Meta.source"/> 
      <short value="Identifies where the resource comes from"/> 
      <definition value="A uri that identifies the source system of the resource. This provides a minimal
       amount of [Provenance](provenance.html#) information that can be used to track
       or differentiate the source of information in the resource. The source may identify
       another FHIR server, document, message, database, etc."/> 
      <comment value="The exact use of the source (and the possible implied Provenance.entity.role and
       agent.role) is left to implementer discretion. Only one nominated source is allowed;
       for additional provenance details, a full Provenance resource should be used. The
       source may correspond to Provenance.entity.what[x] or Provenance.agent.who[x],
       though it may be a more general or abstract reference. 

This element can be used to indicate where the current master source of a resource
       that has a canonical URL if the resource is no longer hosted at the canonical URL."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Meta.source"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="uri"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="Meta.profile">
      <path value="Meta.profile"/> 
      <short value="Profiles this resource claims to conform to"/> 
      <definition value="A list of profiles (references to [StructureDefinition](structuredefinition.html#)
       resources) that this resource claims to conform to. The URL is a reference to [StructureDefin
      ition.url](structuredefinition-definitions.html#StructureDefinition.url)."/> 
      <comment value="It is up to the server and/or other infrastructure of policy to determine whether/how
       these claims are verified and/or updated over time.  The list of profile URLs is
       a set."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="Meta.profile"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="canonical"/> 
        <targetProfile value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="Meta.security">
      <path value="Meta.security"/> 
      <short value="Security Labels applied to this resource"/> 
      <definition value="Security labels applied to this resource. These tags connect specific resources
       to the overall security policy and infrastructure."/> 
      <comment value="The security labels can be updated without changing the stated version of the resource.
       The list of security labels is a set. Uniqueness is based the system/code, and
       version and display are ignored."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="Meta.security"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Coding"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <binding> 
        <extension url="http://hl7.org/fhir/tools/StructureDefinition/binding-definition">
          <valueString value="Security Labels from the Healthcare Privacy and Security Classification System."/> 
        </extension> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="SecurityLabels"/> 
        </extension> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-isCommonBinding">
          <valueBoolean value="true"/> 
        </extension> 
        <strength value="extensible"/> 
        <description value="Security Labels from the Healthcare Privacy and Security Classification System."/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/security-labels"/> 
      </binding> 
    </element> 
    <element id="Meta.tag">
      <path value="Meta.tag"/> 
      <short value="Tags applied to this resource"/> 
      <definition value="Tags applied to this resource. Tags are intended to be used to identify and relate
       resources to process and workflow, and applications are not required to consider
       the tags when interpreting the meaning of a resource."/> 
      <comment value="The tags can be updated without changing the stated version of the resource. The
       list of tags is a set. Uniqueness is based the system/code, and version and display
       are ignored."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="Meta.tag"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Coding"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <binding> 
        <extension url="http://hl7.org/fhir/tools/StructureDefinition/binding-definition">
          <valueString value="Codes that represent various types of tags, commonly workflow-related; e.g. &quot;Needs
           review by Dr. Jones&quot;."/> 
        </extension> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="Tags"/> 
        </extension> 
        <strength value="example"/> 
        <description value="Codes that represent various types of tags, commonly workflow-related; e.g. &quot;Needs
         review by Dr. Jones&quot;."/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/common-tags"/> 
      </binding> 
    </element> 
  </snapshot> 
  <differential> 
    <element id="Meta">
      <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status">
        <valueCode value="normative"/> 
      </extension> 
      <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-normative-version">
        <valueCode value="4.0.0"/> 
      </extension> 
      <path value="Meta"/> 
      <short value="Metadata about a resource"/> 
      <definition value="The metadata about a resource. This is content in the resource 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="*"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="Meta.versionId">
      <path value="Meta.versionId"/> 
      <short value="Version specific identifier"/> 
      <definition value="The version specific identifier, as it appears in the version portion of the URL.
       This value changes when the resource is created, updated, or deleted."/> 
      <comment value="The server assigns this value, and ignores what the client specifies, except in
       the case that the server is imposing version integrity on updates/deletes."/> 
      <min value="0"/> 
      <max value="1"/> 
      <type> 
        <code value="id"/> 
      </type> 
      <isSummary value="true"/> 
    </element> 
    <element id="Meta.lastUpdated">
      <path value="Meta.lastUpdated"/> 
      <short value="When the resource version last changed"/> 
      <definition value="When the resource last changed - e.g. when the version changed."/> 
      <comment value="This element is generally omitted in instances submitted in a PUT or POST. Instead,
       it is populated in the response instance and when retrieving information using
       a GET. The server / resource manager sets this value; what a client provides is
       irrelevant. This is equivalent to the HTTP Last-Modified and SHOULD have the same
       value on a [read](http.html#read) interaction."/> 
      <min value="0"/> 
      <max value="1"/> 
      <type> 
        <code value="instant"/> 
      </type> 
      <isSummary value="true"/> 
    </element> 
    <element id="Meta.source">
      <path value="Meta.source"/> 
      <short value="Identifies where the resource comes from"/> 
      <definition value="A uri that identifies the source system of the resource. This provides a minimal
       amount of [Provenance](provenance.html#) information that can be used to track
       or differentiate the source of information in the resource. The source may identify
       another FHIR server, document, message, database, etc."/> 
      <comment value="The exact use of the source (and the possible implied Provenance.entity.role and
       agent.role) is left to implementer discretion. Only one nominated source is allowed;
       for additional provenance details, a full Provenance resource should be used. The
       source may correspond to Provenance.entity.what[x] or Provenance.agent.who[x],
       though it may be a more general or abstract reference. 

This element can be used to indicate where the current master source of a resource
       that has a canonical URL if the resource is no longer hosted at the canonical URL."/> 
      <min value="0"/> 
      <max value="1"/> 
      <type> 
        <code value="uri"/> 
      </type> 
      <isSummary value="true"/> 
    </element> 
    <element id="Meta.profile">
      <path value="Meta.profile"/> 
      <short value="Profiles this resource claims to conform to"/> 
      <definition value="A list of profiles (references to [StructureDefinition](structuredefinition.html#)
       resources) that this resource claims to conform to. The URL is a reference to [StructureDefin
      ition.url](structuredefinition-definitions.html#StructureDefinition.url)."/> 
      <comment value="It is up to the server and/or other infrastructure of policy to determine whether/how
       these claims are verified and/or updated over time.  The list of profile URLs is
       a set."/> 
      <min value="0"/> 
      <max value="*"/> 
      <type> 
        <code value="canonical"/> 
        <targetProfile value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/> 
      </type> 
      <isSummary value="true"/> 
    </element> 
    <element id="Meta.security">
      <path value="Meta.security"/> 
      <short value="Security Labels applied to this resource"/> 
      <definition value="Security labels applied to this resource. These tags connect specific resources
       to the overall security policy and infrastructure."/> 
      <comment value="The security labels can be updated without changing the stated version of the resource.
       The list of security labels is a set. Uniqueness is based the system/code, and
       version and display are ignored."/> 
      <min value="0"/> 
      <max value="*"/> 
      <type> 
        <code value="Coding"/> 
      </type> 
      <isSummary value="true"/> 
      <binding> 
        <extension url="http://hl7.org/fhir/tools/StructureDefinition/binding-definition">
          <valueString value="Security Labels from the Healthcare Privacy and Security Classification System."/> 
        </extension> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="SecurityLabels"/> 
        </extension> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-isCommonBinding">
          <valueBoolean value="true"/> 
        </extension> 
        <strength value="extensible"/> 
        <description value="Security Labels from the Healthcare Privacy and Security Classification System."/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/security-labels"/> 
      </binding> 
    </element> 
    <element id="Meta.tag">
      <path value="Meta.tag"/> 
      <short value="Tags applied to this resource"/> 
      <definition value="Tags applied to this resource. Tags are intended to be used to identify and relate
       resources to process and workflow, and applications are not required to consider
       the tags when interpreting the meaning of a resource."/> 
      <comment value="The tags can be updated without changing the stated version of the resource. The
       list of tags is a set. Uniqueness is based the system/code, and version and display
       are ignored."/> 
      <min value="0"/> 
      <max value="*"/> 
      <type> 
        <code value="Coding"/> 
      </type> 
      <isSummary value="true"/> 
      <binding> 
        <extension url="http://hl7.org/fhir/tools/StructureDefinition/binding-definition">
          <valueString value="Codes that represent various types of tags, commonly workflow-related; e.g. &quot;Needs
           review by Dr. Jones&quot;."/> 
        </extension> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="Tags"/> 
        </extension> 
        <strength value="example"/> 
        <description value="Codes that represent various types of tags, commonly workflow-related; e.g. &quot;Needs
         review by Dr. Jones&quot;."/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/common-tags"/> 
      </binding> 
    </element> 
  </differential> 
</StructureDefinition> 

Usage note: every effort has been made to ensure that the examples are correct and useful, but they are not a normative part of the specification.