FHIR CI-Build

This is the Continuous Integration Build of FHIR (will be incorrect/inconsistent at times).
See the Directory of published versions

Example StructureDefinition/Linkage (XML)

Patient Care Work GroupMaturity Level: N/AStandards Status: InformativeCompartments: Practitioner

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

Jump past Narrative

StructureDefinition for linkage

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

<StructureDefinition xmlns="http://hl7.org/fhir">
  <id value="Linkage"/> 
  <meta> 
    <lastUpdated value="2024-11-19T23:55:04.453+00:00"/> 
  </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 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="Resource"/>  
            <span title="Linkage : Identifies two or more records (resource instances) that refer to the
             same real-world &quot;occurrence&quot;.">Linkage</span> 
            <a name="Linkage"> </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="versions.html#std-process" style="padding-left: 3px; padding-right: 3px; border: 1px grey solid; font-weight: bold;
             color: black; background-color: #efefef" title="Standards Status = Draft">D</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="domainresource.html">DomainResource</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">Links records for 'same' item
            <br/>  
            <span style="font-style: italic" title="lnk-1">+ Rule: Must have at least two items</span> 
            <br/>  
            <br/>  Elements defined in Ancestors: 
            <a href="resource.html#Resource" title="The logical id of the resource, as used in the URL for the resource. Once assigned,
             this value never changes.">id</a> , 
            <a href="resource.html#Resource" title="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.">meta</a> , 
            <a href="resource.html#Resource" title="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.">implicitRules</a> , 
            <a href="resource.html#Resource" title="The base language in which the resource is written.">language</a> , 
            <a href="domainresource.html#DomainResource" title="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.">text</a> , 
            <a href="domainresource.html#DomainResource" title="These resources do not have an independent existence apart from the resource that
             contains them - they cannot be identified independently, nor can they have their
             own independent transaction scope. This is allowed to be a Parameters resource
             if and only if it is referenced by a resource that provides context/meaning.">contained</a> , 
            <a href="domainresource.html#DomainResource" title="May be used to represent additional information that is not part of the basic definition
             of the resource. To make the use of extensions safe and managable, there is a strict
             set of governance applied to the definition and use of extensions. Though any implementer
             can define an extension, there is a set of requirements that SHALL be met as part
             of the definition of the extension.">extension</a> , 
            <a href="domainresource.html#DomainResource" title="May be used to represent additional information that is not part of the basic definition
             of the resource and that modifies the understanding of the element that contains
             it and/or the understanding of the containing element's descendants. Usually modifier
             elements provide negation or qualification. To make the use of extensions safe
             and managable, there is a strict set of governance applied to the definition and
             use of extensions. Though any implementer is allowed to define an extension, there
             is a set of requirements that SHALL be met as part of the definition of the extension.
             Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or
             DomainResource (including cannot change the meaning of modifierExtension itself).">modifierExtension</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"/>  
            <span title="Linkage.active : Indicates whether the asserted set of linkages are considered
             to be &quot;in effect&quot;.">active</span> 
            <a name="Linkage.active"> </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#boolean">boolean</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px
           #F0F0F0 solid; padding:0px 4px 0px 4px">Whether this linkage assertion is active or not
            <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"/>  
            <span title="Linkage.author : Identifies the user or organization responsible for asserting
             the linkages as well as the user or organization who establishes the context in
             which the nature of each linkage is evaluated.">author</span> 
            <a name="Linkage.author"> </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="references.html#Reference">Reference</a> (
            <a href="practitioner.html">Practitioner</a>  | 
            <a href="practitionerrole.html">PractitionerRole</a>  | 
            <a href="organization.html">Organization</a> )
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">Who is responsible for linkages
            <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/LjIAAAAJUlEQVR4Xu3IIQEAAAg
          DsHd9/w4EQIOamFnaBgAA4MMKAACAKwNp30CqZFfFmwAAAABJRU5ErkJggg==)">
            <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="Element"/>  
            <span title="Linkage.item : Identifies which record considered as the reference to the same
             real-world occurrence as well as how the items should be evaluated within the collection
             of linked items.">item</span> 
            <a name="Linkage.item"> </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> 
            <a href="conformance-rules.html#constraints" style="padding-left: 3px; padding-right: 3px; border: 1px maroon solid; font-weight: bold;
             color: #301212; background-color: #fdf4f4;" title="This element has or is affected by some invariants">C</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px
           #F0F0F0 solid; padding:0px 4px 0px 4px">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="types.html#BackBoneElement">BackboneElement</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px
           #F0F0F0 solid; padding:0px 4px 0px 4px">Item to be linked
            <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/LjIAAAALElEQVR4Xu3IsQ0AIAwEsez6+89AqKGGJj7JzVWS+m
          m3zgcAAMxwDQAAgFcaYAVAgNGLTjgAAAAASUVORK5CYII=)">
            <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: inherit"/> 
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: white; background-color: inherit" title="Primitive Data Type"/>  
            <span title="Linkage.item.type : Distinguishes which item is &quot;source of truth&quot; (if
             any) and which items are no longer considered to be current representations.">type</span> 
            <a name="Linkage.item.type"> </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">1..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#code">code</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">source | alternate | historical
            <br/>  Binding: 
            <a href="valueset-linkage-type.html">Linkage Type</a>  (
            <a href="terminologies.html#required" title="To be conformant, the concept in this element SHALL be from the specified value
             set.">Required</a> )
            <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/LjIAAAAJUlEQVR4Xu3IIQEAAAg
          DsHd9/w4EQIOamFnaBgAA4MMKAACAKwNp30CqZFfFmwAAAABJRU5ErkJggg==)">
            <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: inherit"/> 
            <img alt="." class="hierarchy" src="data:(snipped in html view)" style="background-color: #F7F7F7; background-color: inherit" title="Reference to another Resource"/>  
            <span title="Linkage.item.resource : The resource instance being linked as part of the group.">resource</span> 
            <a name="Linkage.item.resource"> </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">1..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="references.html#Reference">Reference</a> (
            <a href="resourcelist.html">Any</a> )
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px
           #F0F0F0 solid; padding:0px 4px 0px 4px">Resource being linked
            <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="draft"/> 
  </extension> 
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-wg">
    <valueCode value="pc"/> 
  </extension> 
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm">
    <valueInteger value="0"/> 
  </extension> 
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-security-category">
    <valueCode value="patient"/> 
  </extension> 
  <url value="http://hl7.org/fhir/StructureDefinition/Linkage"/> 
  <version value="6.0.0-ballot2"/> 
  <name value="Linkage"/> 
  <status value="draft"/> 
  <experimental value="true"/> 
  <date value="2024-11-19T23:55:04+00:00"/> 
  <publisher value="HL7 International / Patient Care"/> 
  <contact> 
    <telecom> 
      <system value="url"/> 
      <value value="http://www.hl7.org/Special/committees/fiwg"/> 
    </telecom> 
  </contact> 
  <contact> 
    <telecom> 
      <system value="url"/> 
      <value value="http://www.hl7.org/Special/committees/patientcare"/> 
    </telecom> 
  </contact> 
  <description value="Identifies two or more records (resource instances) that refer to the same real-world
   &quot;occurrence&quot;."/> 
  <jurisdiction> 
    <coding> 
      <system value="http://unstats.un.org/unsd/methods/m49/m49.htm"/> 
      <code value="001"/> 
      <display value="World"/> 
    </coding> 
  </jurisdiction> 
  <fhirVersion value="6.0.0-ballot2"/> 
  <mapping> 
    <identity value="w5"/> 
    <uri value="http://hl7.org/fhir/fivews"/> 
    <name value="FiveWs Pattern Mapping"/> 
  </mapping> 
  <mapping> 
    <identity value="rim"/> 
    <uri value="http://hl7.org/v3"/> 
    <name value="RIM Mapping"/> 
  </mapping> 
  <kind value="resource"/> 
  <abstract value="false"/> 
  <type value="Linkage"/> 
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/DomainResource"/> 
  <derivation value="specialization"/> 
  <snapshot> 
    <element id="Linkage">
      <path value="Linkage"/> 
      <short value="Links records for 'same' item"/> 
      <definition value="Identifies two or more records (resource instances) that refer to the same real-world
       &quot;occurrence&quot;."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="Linkage"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <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()"/> 
        <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((('#'+id in (%resource.descendants().reference | %resource.descendants().ofTy
        pe(canonical) | %resource.descendants().ofType(uri) | %resource.descendants().ofType(url)))
         or descendants().where(reference = '#').exists() or descendants().where(ofType(canonical)
         = '#').exists() or descendants().where(ofType(canonical) = '#').exists()).not()).trace('unmat
        ched', id).empty()"/> 
        <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()"/> 
        <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()"/> 
        <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()"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/DomainResource"/> 
      </constraint> 
      <constraint> 
        <key value="lnk-1"/> 
        <severity value="error"/> 
        <human value="Must have at least two items"/> 
        <expression value="item.count()&gt;1"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Linkage"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="Entity, Role, or Act,N/A - RIM doesn't know how to do this"/> 
      </mapping> 
      <mapping> 
        <identity value="w5"/> 
        <map value="infrastructure.structure"/> 
      </mapping> 
    </element> 
    <element id="Linkage.id">
      <path value="Linkage.id"/> 
      <short value="Logical id of this artifact"/> 
      <definition value="The logical id of the resource, as used in the URL for the resource. Once assigned,
       this value never changes."/> 
      <comment value="Within the context of the FHIR RESTful interactions, the resource has an id except
       for cases like the create and conditional update. Otherwise, the use of the resouce
       id depends on the given use case."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Resource.id"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <!--  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> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="Linkage.meta">
      <path value="Linkage.meta"/> 
      <short value="Metadata about the resource"/> 
      <definition value="The metadata about the resource. This is content that is maintained by the infrastructure.
       Changes to the content might not always be associated with version changes to the
       resource."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Resource.meta"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="Meta"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="Linkage.implicitRules">
      <path value="Linkage.implicitRules"/> 
      <short value="A set of rules under which this content was created"/> 
      <definition value="A reference to a set of rules that were followed when the resource was constructed,
       and which must be understood when processing the content. Often, this is a reference
       to an implementation guide that defines the special rules along with other profiles
       etc."/> 
      <comment value="Asserting this rule set restricts the content to be only understood by a limited
       set of trading partners. This inherently limits the usefulness of the data in the
       long term. However, the existing health eco-system is highly fractured, and not
       yet ready to define, collect, and exchange data in a generally computable sense.
       Wherever possible, implementers and/or specification writers should avoid using
       this element. Often, when used, the URL is a reference to an implementation guide
       that defines these special rules as part of its narrative along with other profiles,
       value sets, etc."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Resource.implicitRules"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="uri"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="true"/> 
      <isModifierReason value="This element is labeled as a modifier because the implicit rules may provide additional
       knowledge about the resource that modifies its meaning or interpretation"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="Linkage.language">
      <path value="Linkage.language"/> 
      <short value="Language of the resource content"/> 
      <definition value="The base language in which the resource is written."/> 
      <comment value="Language is provided to support indexing and accessibility (typically, services
       such as text to speech use the language tag). The html language tag in the narrative
       applies  to the narrative. The language tag on the resource may be used to specify
       the language of other presentations generated from the data in the resource. Not
       all the content has to be in the base language. The Resource.language should not
       be assumed to apply to the narrative automatically. If a language is specified,
       it should it also be specified on the div element in the html (see rules in HTML5
       for information about the relationship between xml:lang and the html lang attribute)."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Resource.language"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="code"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <binding> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="Language"/> 
        </extension> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-isCommonBinding">
          <valueBoolean value="true"/> 
        </extension> 
        <strength value="required"/> 
        <description value="IETF language tag for a human language"/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/all-languages|6.0.0-ballot2"/> 
        <additional> 
          <purpose value="starter"/> 
          <valueSet value="http://hl7.org/fhir/ValueSet/languages"/> 
        </additional> 
      </binding> 
    </element> 
    <element id="Linkage.text">
      <path value="Linkage.text"/> 
      <short value="Text summary of the resource, for human interpretation"/> 
      <definition value="A human-readable narrative that contains a summary of the resource and can be used
       to represent the content of the resource to a human. The narrative need not encode
       all the structured data, but is required to contain sufficient detail to make it
       &quot;clinically safe&quot; for a human to just read the narrative. Resource definitions
       may define what content should be represented in the narrative to ensure clinical
       safety."/> 
      <comment value="Contained resources do not have a narrative. Resources that are not contained SHOULD
       have a narrative. In some cases, a resource may only have text with little or no
       additional discrete data (as long as all minOccurs=1 elements are satisfied). 
       This may be necessary for data from legacy systems where information is captured
       as a &quot;text blob&quot; or where text is additionally entered raw or narrated
       and encoded information is added later."/> 
      <alias value="narrative"/> 
      <alias value="html"/> 
      <alias value="xhtml"/> 
      <alias value="display"/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="DomainResource.text"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="Narrative"/> 
      </type> 
      <condition value="dom-6"/> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="Act.text?"/> 
      </mapping> 
    </element> 
    <element id="Linkage.contained">
      <path value="Linkage.contained"/> 
      <short value="Contained, inline Resources"/> 
      <definition value="These resources do not have an independent existence apart from the resource that
       contains them - they cannot be identified independently, nor can they have their
       own independent transaction scope. This is allowed to be a Parameters resource
       if and only if it is referenced by a resource that provides context/meaning."/> 
      <comment value="This should never be done when the content can be identified properly, as once
       identification is lost, it is extremely difficult (and context dependent) to restore
       it again. Contained resources may have profiles and tags in their meta elements,
       but SHALL NOT have security labels."/> 
      <alias value="inline resources"/> 
      <alias value="anonymous resources"/> 
      <alias value="contained resources"/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="DomainResource.contained"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Resource"/> 
      </type> 
      <condition value="dom-2"/> 
      <condition value="dom-4"/> 
      <condition value="dom-3"/> 
      <condition value="dom-5"/> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="Linkage.extension">
      <path value="Linkage.extension"/> 
      <short value="Additional content defined by implementations"/> 
      <definition value="May be used to represent additional information that is not part of the basic definition
       of the resource. To make the use of extensions safe and managable, there is a strict
       set of governance applied to the definition and use of extensions. Though any implementer
       can define an extension, there is a set of requirements that SHALL be met as part
       of the definition of the extension."/> 
      <comment value="There can be no stigma associated with the use of extensions by any application,
       project, or standard - regardless of the institution or jurisdiction that uses
       or defines the extensions.  The use of extensions is what allows the FHIR specification
       to retain a core level of simplicity for everyone."/> 
      <alias value="extensions"/> 
      <alias value="user content"/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="DomainResource.extension"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Extension"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="Linkage.modifierExtension">
      <path value="Linkage.modifierExtension"/> 
      <short value="Extensions that cannot be ignored"/> 
      <definition value="May be used to represent additional information that is not part of the basic definition
       of the resource and that modifies the understanding of the element that contains
       it and/or the understanding of the containing element's descendants. Usually modifier
       elements provide negation or qualification. To make the use of extensions safe
       and managable, there is a strict set of governance applied to the definition and
       use of extensions. Though any implementer is allowed to define an extension, there
       is a set of requirements that SHALL be met as part of the definition of the extension.
       Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or
       DomainResource (including cannot change the meaning of modifierExtension itself)."/> 
      <comment value="There can be no stigma associated with the use of extensions by any application,
       project, or standard - regardless of the institution or jurisdiction that uses
       or defines the extensions.  The use of extensions is what allows the FHIR specification
       to retain a core level of simplicity for everyone."/> 
      <requirements value="Modifier extensions allow for extensions that *cannot* be safely ignored to be
       clearly distinguished from the vast majority of extensions which can be safely
       ignored.  This promotes interoperability by eliminating the need for implementers
       to prohibit the presence of extensions. For further information, see the [definition
       of modifier extensions](extensibility.html#modifierExtension)."/> 
      <alias value="extensions"/> 
      <alias value="user content"/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="DomainResource.modifierExtension"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Extension"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="true"/> 
      <isModifierReason value="Modifier extensions are expected to modify the meaning or interpretation of the
       resource that contains them"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="Linkage.active">
      <path value="Linkage.active"/> 
      <short value="Whether this linkage assertion is active or not"/> 
      <definition value="Indicates whether the asserted set of linkages are considered to be &quot;in effect&quot;."/> 
      <comment value="If false, any asserted linkages should not be considered current/relevant/applicable."/> 
      <requirements value="Need to be able to mark a linkage record as not to be used because it was created
       in error."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Linkage.active"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="boolean"/> 
      </type> 
      <meaningWhenMissing value="This resource is generally assumed to be active if no value is provided for the
       active element"/> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.status"/> 
      </mapping> 
    </element> 
    <element id="Linkage.author">
      <path value="Linkage.author"/> 
      <short value="Who is responsible for linkages"/> 
      <definition value="Identifies the user or organization responsible for asserting the linkages as well
       as the user or organization who establishes the context in which the nature of
       each linkage is evaluated."/> 
      <requirements value="&quot;Primary&quot; for the same set of linked resources may be different from
       different user's/organization's perspectives."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Linkage.author"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="Reference"/> 
        <targetProfile value="http://hl7.org/fhir/StructureDefinition/Practitioner"/> 
        <targetProfile value="http://hl7.org/fhir/StructureDefinition/PractitionerRole"/> 
        <targetProfile value="http://hl7.org/fhir/StructureDefinition/Organization"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.author"/> 
      </mapping> 
    </element> 
    <element id="Linkage.item">
      <path value="Linkage.item"/> 
      <short value="Item to be linked"/> 
      <definition value="Identifies which record considered as the reference to the same real-world occurrence
       as well as how the items should be evaluated within the collection of linked items."/> 
      <min value="1"/> 
      <max value="*"/> 
      <base> 
        <path value="Linkage.item"/> 
        <min value="1"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="BackboneElement"/> 
      </type> 
      <condition value="lnk-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())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="Linkage.item.id">
      <path value="Linkage.item.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="string"/> 
        </extension> 
        <code value="http://hl7.org/fhirpath/System.String"/> 
      </type> 
      <condition value="ele-1"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="n/a"/> 
      </mapping> 
    </element> 
    <element id="Linkage.item.extension">
      <path value="Linkage.item.extension"/> 
      <short value="Additional content defined by implementations"/> 
      <definition value="May be used to represent additional information that is not part of the basic definition
       of the element. To make the use of extensions safe and managable, there is a strict
       set of governance applied to the definition and use of extensions. Though any implementer
       can define an extension, there is a set of requirements that SHALL be met as part
       of the definition of the extension."/> 
      <comment value="There can be no stigma associated with the use of extensions by any application,
       project, or standard - regardless of the institution or jurisdiction that uses
       or defines the extensions.  The use of extensions is what allows the FHIR specification
       to retain a core level of simplicity for everyone."/> 
      <alias value="extensions"/> 
      <alias value="user content"/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="Element.extension"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Extension"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="n/a"/> 
      </mapping> 
    </element> 
    <element id="Linkage.item.modifierExtension">
      <path value="Linkage.item.modifierExtension"/> 
      <short value="Extensions that cannot be ignored even if unrecognized"/> 
      <definition value="May be used to represent additional information that is not part of the basic definition
       of the element and that modifies the understanding of the element in which it is
       contained and/or the understanding of the containing element's descendants. Usually
       modifier elements provide negation or qualification. To make the use of extensions
       safe and managable, there is a strict set of governance applied to the definition
       and use of extensions. Though any implementer can define an extension, there is
       a set of requirements that SHALL be met as part of the definition of the extension.
       Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or
       DomainResource (including cannot change the meaning of modifierExtension itself)."/> 
      <comment value="There can be no stigma associated with the use of extensions by any application,
       project, or standard - regardless of the institution or jurisdiction that uses
       or defines the extensions.  The use of extensions is what allows the FHIR specification
       to retain a core level of simplicity for everyone."/> 
      <requirements value="Modifier extensions allow for extensions that *cannot* be safely ignored to be
       clearly distinguished from the vast majority of extensions which can be safely
       ignored.  This promotes interoperability by eliminating the need for implementers
       to prohibit the presence of extensions. For further information, see the [definition
       of modifier extensions](extensibility.html#modifierExtension)."/> 
      <alias value="extensions"/> 
      <alias value="user content"/> 
      <alias value="modifiers"/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="BackboneElement.modifierExtension"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Extension"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <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="Linkage.item.type">
      <path value="Linkage.item.type"/> 
      <short value="source | alternate | historical"/> 
      <definition value="Distinguishes which item is &quot;source of truth&quot; (if any) and which items
       are no longer considered to be current representations."/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="Linkage.item.type"/> 
        <min value="1"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="code"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <binding> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="LinkageType"/> 
        </extension> 
        <strength value="required"/> 
        <description value="Used to distinguish different roles a resource can play within a set of linked
         resources."/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/linkage-type|6.0.0-ballot2"/> 
      </binding> 
    </element> 
    <element id="Linkage.item.resource">
      <path value="Linkage.item.resource"/> 
      <short value="Resource being linked"/> 
      <definition value="The resource instance being linked as part of the group."/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="Linkage.item.resource"/> 
        <min value="1"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="Reference"/> 
        <targetProfile value="http://hl7.org/fhir/StructureDefinition/Resource"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
  </snapshot> 
  <differential> 
    <element id="Linkage">
      <path value="Linkage"/> 
      <short value="Links records for 'same' item"/> 
      <definition value="Identifies two or more records (resource instances) that refer to the same real-world
       &quot;occurrence&quot;."/> 
      <min value="0"/> 
      <max value="*"/> 
      <constraint> 
        <key value="lnk-1"/> 
        <severity value="error"/> 
        <human value="Must have at least two items"/> 
        <expression value="item.count()&gt;1"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Linkage"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <mapping> 
        <identity value="w5"/> 
        <map value="infrastructure.structure"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A - RIM doesn't know how to do this"/> 
      </mapping> 
    </element> 
    <element id="Linkage.active">
      <path value="Linkage.active"/> 
      <short value="Whether this linkage assertion is active or not"/> 
      <definition value="Indicates whether the asserted set of linkages are considered to be &quot;in effect&quot;."/> 
      <comment value="If false, any asserted linkages should not be considered current/relevant/applicable."/> 
      <requirements value="Need to be able to mark a linkage record as not to be used because it was created
       in error."/> 
      <min value="0"/> 
      <max value="1"/> 
      <type> 
        <code value="boolean"/> 
      </type> 
      <meaningWhenMissing value="This resource is generally assumed to be active if no value is provided for the
       active element"/> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.status"/> 
      </mapping> 
    </element> 
    <element id="Linkage.author">
      <path value="Linkage.author"/> 
      <short value="Who is responsible for linkages"/> 
      <definition value="Identifies the user or organization responsible for asserting the linkages as well
       as the user or organization who establishes the context in which the nature of
       each linkage is evaluated."/> 
      <requirements value="&quot;Primary&quot; for the same set of linked resources may be different from
       different user's/organization's perspectives."/> 
      <min value="0"/> 
      <max value="1"/> 
      <type> 
        <code value="Reference"/> 
        <targetProfile value="http://hl7.org/fhir/StructureDefinition/Practitioner"/> 
        <targetProfile value="http://hl7.org/fhir/StructureDefinition/PractitionerRole"/> 
        <targetProfile value="http://hl7.org/fhir/StructureDefinition/Organization"/> 
      </type> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.author"/> 
      </mapping> 
    </element> 
    <element id="Linkage.item">
      <path value="Linkage.item"/> 
      <short value="Item to be linked"/> 
      <definition value="Identifies which record considered as the reference to the same real-world occurrence
       as well as how the items should be evaluated within the collection of linked items."/> 
      <min value="1"/> 
      <max value="*"/> 
      <type> 
        <code value="BackboneElement"/> 
      </type> 
      <condition value="lnk-1"/> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="Linkage.item.type">
      <path value="Linkage.item.type"/> 
      <short value="source | alternate | historical"/> 
      <definition value="Distinguishes which item is &quot;source of truth&quot; (if any) and which items
       are no longer considered to be current representations."/> 
      <min value="1"/> 
      <max value="1"/> 
      <type> 
        <code value="code"/> 
      </type> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <binding> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="LinkageType"/> 
        </extension> 
        <strength value="required"/> 
        <description value="Used to distinguish different roles a resource can play within a set of linked
         resources."/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/linkage-type|6.0.0-ballot2"/> 
      </binding> 
    </element> 
    <element id="Linkage.item.resource">
      <path value="Linkage.item.resource"/> 
      <short value="Resource being linked"/> 
      <definition value="The resource instance being linked as part of the group."/> 
      <min value="1"/> 
      <max value="1"/> 
      <type> 
        <code value="Reference"/> 
        <targetProfile value="http://hl7.org/fhir/StructureDefinition/Resource"/> 
      </type> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </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.