Extensions for Using Data Elements from FHIR R5 in FHIR R4
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Extensions for Using Data Elements from FHIR R5 in FHIR R4 - Downloaded Version null See the Directory of published versions

Extension: ExtensionObservation_Value - XML Profile

Page standards status: Trial-use Maturity Level: 0

XML representation of the ext-R5-Observation.value extension.

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<StructureDefinition xmlns="http://hl7.org/fhir">
  <id value="ext-R5-Observation.value"/>
  <text>
    <status value="extensions"/>
    <div xmlns="http://www.w3.org/1999/xhtml"><p class="res-header-id"><b>Generated Narrative: StructureDefinition ext-R5-Observation.value</b></p><a name="ext-R5-Observation.value"> </a><a name="hcext-R5-Observation.value"> </a><table border="0" cellpadding="0" cellspacing="0" style="border: 0px #F0F0F0 solid; font-size: 11px; font-family: verdana; vertical-align: top;"><tr style="border: 1px #F0F0F0 solid; font-size: 11px; font-family: verdana; vertical-align: top"><th style="vertical-align: top; text-align : var(--ig-left,left); background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; padding-top: 3px; padding-bottom: 3px" class="hierarchy"><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="The logical name of the element">Name</a></th><th style="vertical-align: top; text-align : var(--ig-left,left); background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; padding-top: 3px; padding-bottom: 3px" class="hierarchy"><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Information about the use of the element">Flags</a></th><th style="vertical-align: top; text-align : var(--ig-left,left); background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; padding-top: 3px; padding-bottom: 3px" class="hierarchy"><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Minimum and Maximum # of times the element can appear in the instance">Card.</a></th><th style="vertical-align: top; text-align : var(--ig-left,left); background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; padding-top: 3px; padding-bottom: 3px; width: 100px" class="hierarchy"><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Reference to the type of the element">Type</a></th><th style="vertical-align: top; text-align : var(--ig-left,left); background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; padding-top: 3px; padding-bottom: 3px" class="hierarchy"><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Additional information about the element">Description &amp; Constraints</a><span style="float: right"><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Legend for this format"><img src="data:image/png;base64,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" alt="doco" style="background-color: inherit"/></a></span></th></tr><tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color: white"><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; white-space: nowrap; background-image: url(tbl_bck1.png)" class="hierarchy"><img src="tbl_spacer.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="icon_element.gif" alt="." style="background-color: white; background-color: inherit" title="Element" class="hierarchy"/> <a href="StructureDefinition-ext-R5-Observation.value-definitions.html#Extension" title="R5: `Observation.value[x]` additional types (Attachment, Reference(http://hl7.org/fhir/StructureDefinition/MolecularSequence))">Extension</a><a name="Extension"> </a></td><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy">0..1</td><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a href="http://hl7.org/fhir/R4/extensibility.html#Extension">Extension(4.0.1)</a></td><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy">R5: value additional types<br/></td></tr>
<tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color: #F7F7F7"><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; white-space: nowrap; background-image: url(tbl_bck10.png)" class="hierarchy"><img src="tbl_spacer.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="tbl_vjoin.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="icon_element.gif" alt="." style="background-color: #F7F7F7; background-color: inherit" title="Element" class="hierarchy"/> <a href="StructureDefinition-ext-R5-Observation.value-definitions.html#Extension.url">url</a><a name="Extension.url"> </a></td><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy">1..1</td><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a style="opacity: 0.5; opacity: 0.5" href="http://hl7.org/fhir/R4/datatypes.html#uri">uri</a></td><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="color: darkgreen">&quot;http://hl7.org/fhir/5.0/StructureDefinition/extension-Observation.value&quot;</span></td></tr>
<tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color: white"><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; white-space: nowrap; background-image: url(tbl_bck01.png)" class="hierarchy"><img src="tbl_spacer.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="tbl_vjoin_end.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="icon_choice.gif" alt="." style="background-color: white; background-color: inherit" title="Choice of Types" class="hierarchy"/> <a href="StructureDefinition-ext-R5-Observation.value-definitions.html#Extension.value[x]" title="The information determined as a result of making the observation, if the information has a simple value.">value[x]</a><a name="Extension.value_x_"> </a></td><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy">0..1</td><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy">Actual result</td></tr>
<tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color: #F7F7F7"><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; white-space: nowrap; background-image: url(tbl_bck010.png)" class="hierarchy"><img src="tbl_spacer.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="tbl_blank.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="tbl_vjoin.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="icon_datatype.gif" alt="." style="background-color: #F7F7F7; background-color: inherit" title="Data Type" class="hierarchy"/> <span title="Base StructureDefinition for Attachment Type: For referring to data content defined in other formats.">valueAttachment</span></td><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a href="http://hl7.org/fhir/R4/datatypes.html#Attachment">Attachment</a></td><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/></tr>
<tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color: white"><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; white-space: nowrap; background-image: url(tbl_bck000.png)" class="hierarchy"><img src="tbl_spacer.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="tbl_blank.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="tbl_vjoin_end.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="icon_reference.png" alt="." style="background-color: white; background-color: inherit" title="Reference to another Resource" class="hierarchy"/> valueReference</td><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a href="http://hl7.org/fhir/R4/references.html#Reference">Reference</a>(<a href="StructureDefinition-profile-MolecularSequence.html">Cross-version Profile for R5.MolecularSequence for use in FHIR R4(0.1.0)</a> | <a href="http://hl7.org/fhir/R4/molecularsequence.html">MolecularSequence</a>)</td><td style="vertical-align: top; text-align : var(--ig-left,left); background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/></tr>
<tr><td colspan="5" class="hierarchy"><br/><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Legend for this format"><img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAABmJLR0QA/wD/AP+gvaeTAAAACXBIWXMAAAsTAAALEwEAmpwYAAAAB3RJTUUH3goXBCwdPqAP0wAAAldJREFUOMuNk0tIlFEYhp9z/vE2jHkhxXA0zJCMitrUQlq4lnSltEqCFhFG2MJFhIvIFpkEWaTQqjaWZRkp0g26URZkTpbaaOJkDqk10szoODP//7XIMUe0elcfnPd9zsfLOYplGrpRwZaqTtw3K7PtGem7Q6FoidbGgqHVy/HRb669R+56zx7eRV1L31JGxYbBtjKK93cxeqfyQHbehkZbUkK20goELEuIzEd+dHS+qz/Y8PTSif0FnGkbiwcAjHaU1+QWOptFiyCLp/LnKptpqIuXHx6rbR26kJcBX3yLgBfnd7CxwJmflpP2wUg0HIAoUUpZBmKzELGWcN8nAr6Gpu7tLU/CkwAaoKTWRSQyt89Q8w6J+oVQkKnBoblH7V0PPvUOvDYXfopE/SJmALsxnVm6LbkotrUtNowMeIrVrBcBpaMmdS0j9df7abpSuy7HWehwJdt1lhVwi/J58U5beXGAF6c3UXLycw1wdFklArBn87xdh0ZsZtArghBdAA3+OEDVubG4UEzP6x1FOWneHh2VDAHBAt80IbdXDcesNoCvs3E5AFyNSU5nbrDPZpcUEQQTFZiEVx+51fxMhhyJEAgvlriadIJZZksRuwBYMOPBbO3hePVVqgEJhFeUuFLhIPkRP6BQLIBrmMenujm/3g4zc398awIe90Zb5A1vREALqneMcYgP/xVQWlG+Ncu5vgwwlaUNx+3799rfe96u9K0JSDXcOzOTJg4B6IgmXfsygc7/Bvg9g9E58/cDVmGIBOP/zT8Bz1zqWqpbXIsd0O9hajXfL6u4BaOS6SeWAAAAAElFTkSuQmCC" alt="doco" style="background-color: inherit"/> Documentation for this format</a></td></tr></table></div>
  </text>
  <extension
             url="http://hl7.org/fhir/StructureDefinition/structuredefinition-wg">
    <valueCode value="fhir"/>
  </extension>
  <extension url="http://hl7.org/fhir/StructureDefinition/package-source">
    <extension url="packageId">
      <valueId value="hl7.fhir.uv.xver-r5.r4"/>
    </extension>
    <extension url="version">
      <valueString value="0.1.0"/>
    </extension>
    <extension url="uri">
      <valueUri
                value="http://hl7.org/fhir/uv/xver/ImplementationGuide/hl7.fhir.uv.xver-r5.r4"/>
    </extension>
  </extension>
  <extension
             url="http://hl7.org/fhir/StructureDefinition/version-specific-use">
    <extension url="startFhirVersion">
      <valueCode value="4.0"/>
    </extension>
    <extension url="endFhirVersion">
      <valueCode value="4.0"/>
    </extension>
  </extension>
  <extension
             url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm">
    <valueInteger value="0">
      <extension
                 url="http://hl7.org/fhir/StructureDefinition/structuredefinition-conformance-derivedFrom">
        <valueCanonical
                        value="http://hl7.org/fhir/uv/xver/ImplementationGuide/hl7.fhir.uv.xver-r5.r4"/>
      </extension>
    </valueInteger>
  </extension>
  <extension
             url="http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status">
    <valueCode value="trial-use">
      <extension
                 url="http://hl7.org/fhir/StructureDefinition/structuredefinition-conformance-derivedFrom">
        <valueCanonical
                        value="http://hl7.org/fhir/uv/xver/ImplementationGuide/hl7.fhir.uv.xver-r5.r4"/>
      </extension>
    </valueCode>
  </extension>
  <url
       value="http://hl7.org/fhir/5.0/StructureDefinition/extension-Observation.value"/>
  <version value="0.1.0"/>
  <name value="ExtensionObservation_Value"/>
  <title value="R5: value additional types"/>
  <status value="active"/>
  <experimental value="false"/>
  <date value="2026-03-17T21:02:03.8104715+00:00"/>
  <publisher value="FHIR Infrastructure"/>
  <contact>
    <name value="FHIR Infrastructure"/>
    <telecom>
      <system value="url"/>
      <value value="http://www.hl7.org/Special/committees/fiwg"/>
    </telecom>
  </contact>
  <description
               value="R5: `Observation.value[x]` additional types (Attachment, Reference(http://hl7.org/fhir/StructureDefinition/MolecularSequence))"/>
  <jurisdiction>
    <coding>
      <system value="http://unstats.un.org/unsd/methods/m49/m49.htm"/>
      <code value="001"/>
      <display value="World"/>
    </coding>
  </jurisdiction>
  <purpose
           value="This extension is part of the cross-version definitions generated to enable use of the
element `Observation.value[x]` as defined in FHIR R5
in FHIR R4.

The source element is defined as:
`Observation.value[x]` 0..1 `Attachment, boolean, CodeableConcept, dateTime, integer, Period, Quantity, Range, Ratio, Reference(http://hl7.org/fhir/StructureDefinition/MolecularSequence), SampledData, string, time`

Across FHIR versions, the element set has been mapped as:
*  R5: `Observation.value[x]` 0..1 `Attachment, boolean, CodeableConcept, dateTime, integer, Period, Quantity, Range, Ratio, Reference(http://hl7.org/fhir/StructureDefinition/MolecularSequence), SampledData, string, time`
*  R4B: `Observation.value[x]` 0..1 `boolean, CodeableConcept, dateTime, integer, Period, Quantity, Range, Ratio, SampledData, string, time`
*  R4: `Observation.value[x]` 0..1 `boolean, CodeableConcept, dateTime, integer, Period, Quantity, Range, Ratio, SampledData, string, time`

Following are the generation technical comments:
Element `Observation.value[x]` is mapped to FHIR R4 element `Observation.value[x]` as `SourceIsBroaderThanTarget`.
The mappings for `Observation.value[x]` do not cover the following types: Attachment, Reference.
The target context `Observation.value[x]` is a choice-type element and cannot directly hold extensions. The context is moved up to parent element `Observation`."/>
  <fhirVersion value="4.0.1"/>
  <mapping>
    <identity value="rim"/>
    <uri value="http://hl7.org/v3"/>
    <name value="RIM Mapping"/>
  </mapping>
  <kind value="complex-type"/>
  <abstract value="false"/>
  <context>
    <type value="element"/>
    <expression value="Observation"/>
  </context>
  <type value="Extension"/>
  <baseDefinition
                  value="http://hl7.org/fhir/StructureDefinition/Extension|4.0.1"/>
  <derivation value="constraint"/>
  <snapshot>
    <extension
               url="http://hl7.org/fhir/tools/StructureDefinition/snapshot-base-version">
      <valueString value="4.0.1"/>
    </extension>
    <element id="Extension">
      <path value="Extension"/>
      <short value="R5: value additional types"/>
      <definition
                  value="R5: `Observation.value[x]` additional types (Attachment, Reference(http://hl7.org/fhir/StructureDefinition/MolecularSequence))"/>
      <comment
               value="Element `Observation.value[x]` is mapped to FHIR R4 element `Observation.value[x]` as `SourceIsBroaderThanTarget`.
The mappings for `Observation.value[x]` do not cover the following types: Attachment, Reference.
The target context `Observation.value[x]` is a choice-type element and cannot directly hold extensions. The context is moved up to parent element `Observation`.
- An observation may have:
  1.  a single value here
  1.  both a value and a set of related or component values
  1.  only a set of related or component values.
-  If a value is present, the datatype for this element should be determined by the `code`.
-  *CodeableConcept* with just a text would be used instead of a string if the field was usually coded, or if the type associated with the `code` defines a coded value.
-  *Attachment* is used if the observation result value is a binary file such as an image.  If the observation result value is derived from the binary file (for example 'X' detected and here is the the proof in this image), the binary file may be directly represented using *DocumentReference* and referenced by `derivedFrom`.
- The usage of valueReference is restricted to the MolecularSequence resource when used as a definitional resource, not as a patient-specific finding. .
- For additional guidance, see the [Notes section](https://hl7.org/fhir/observ.html#notes) below."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="Extension"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <condition value="ele-1"/>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression
                    value="hasValue() or (children().count() &gt; id.count())"/>
        <xpath value="@value|f:*|h:div"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/Element|4.0.1"/>
      </constraint>
      <constraint>
        <key value="ext-1"/>
        <severity value="error"/>
        <human value="Must have either extensions or value[x], not both"/>
        <expression value="extension.exists() != value.exists()"/>
        <xpath
               value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), 'value')])"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/Extension|4.0.1"/>
      </constraint>
      <isModifier value="false"/>
    </element>
    <element id="Extension.id">
      <path value="Extension.id"/>
      <representation value="xmlAttr"/>
      <short value="Unique id for inter-element referencing"/>
      <definition
                  value="Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="Element.id"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
          <valueUrl value="string"/>
        </extension>
        <code value="http://hl7.org/fhirpath/System.String"/>
      </type>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="n/a"/>
      </mapping>
    </element>
    <element id="Extension.extension">
      <path value="Extension.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 manageable, there is a strict set of governance  applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension."/>
      <comment
               value="There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions.  The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone."/>
      <alias value="extensions"/>
      <alias value="user content"/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="Element.extension"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="Extension"/>
      </type>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression
                    value="hasValue() or (children().count() &gt; id.count())"/>
        <xpath value="@value|f:*|h:div"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/Element|4.0.1"/>
      </constraint>
      <constraint>
        <key value="ext-1"/>
        <severity value="error"/>
        <human value="Must have either extensions or value[x], not both"/>
        <expression value="extension.exists() != value.exists()"/>
        <xpath
               value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/Extension|4.0.1"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="n/a"/>
      </mapping>
    </element>
    <element id="Extension.url">
      <path value="Extension.url"/>
      <representation value="xmlAttr"/>
      <short value="identifies the meaning of the extension"/>
      <definition
                  value="Source of the definition for the extension code - a logical name or a URL."/>
      <comment
               value="The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="Extension.url"/>
        <min value="1"/>
        <max value="1"/>
      </base>
      <type>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
          <valueUrl value="uri"/>
        </extension>
        <code value="http://hl7.org/fhirpath/System.String"/>
      </type>
      <fixedUri
                value="http://hl7.org/fhir/5.0/StructureDefinition/extension-Observation.value"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="N/A"/>
      </mapping>
    </element>
    <element id="Extension.value[x]">
      <path value="Extension.value[x]"/>
      <short value="Actual result"/>
      <definition
                  value="The information determined as a result of making the observation, if the information has a simple value."/>
      <comment
               value="- An observation may have:
  1.  a single value here
  1.  both a value and a set of related or component values
  1.  only a set of related or component values.
-  If a value is present, the datatype for this element should be determined by the `code`.
-  *CodeableConcept* with just a text would be used instead of a string if the field was usually coded, or if the type associated with the `code` defines a coded value.
-  *Attachment* is used if the observation result value is a binary file such as an image.  If the observation result value is derived from the binary file (for example 'X' detected and here is the the proof in this image), the binary file may be directly represented using *DocumentReference* and referenced by `derivedFrom`.
- The usage of valueReference is restricted to the MolecularSequence resource when used as a definitional resource, not as a patient-specific finding. .
- For additional guidance, see the [Notes section](https://hl7.org/fhir/observ.html#notes) below."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="Extension.value[x]"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="Attachment"/>
      </type>
      <type>
        <code value="Reference"/>
        <targetProfile
                       value="http://hl7.org/fhir/5.0/StructureDefinition/profile-MolecularSequence|0.1.0"/>
        <targetProfile
                       value="http://hl7.org/fhir/StructureDefinition/MolecularSequence|4.0.1"/>
      </type>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression
                    value="hasValue() or (children().count() &gt; id.count())"/>
        <xpath value="@value|f:*|h:div"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/Element|4.0.1"/>
      </constraint>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="N/A"/>
      </mapping>
    </element>
  </snapshot>
  <differential>
    <element id="Extension">
      <path value="Extension"/>
      <short value="R5: value additional types"/>
      <definition
                  value="R5: `Observation.value[x]` additional types (Attachment, Reference(http://hl7.org/fhir/StructureDefinition/MolecularSequence))"/>
      <comment
               value="Element `Observation.value[x]` is mapped to FHIR R4 element `Observation.value[x]` as `SourceIsBroaderThanTarget`.
The mappings for `Observation.value[x]` do not cover the following types: Attachment, Reference.
The target context `Observation.value[x]` is a choice-type element and cannot directly hold extensions. The context is moved up to parent element `Observation`.
- An observation may have:
  1.  a single value here
  1.  both a value and a set of related or component values
  1.  only a set of related or component values.
-  If a value is present, the datatype for this element should be determined by the `code`.
-  *CodeableConcept* with just a text would be used instead of a string if the field was usually coded, or if the type associated with the `code` defines a coded value.
-  *Attachment* is used if the observation result value is a binary file such as an image.  If the observation result value is derived from the binary file (for example 'X' detected and here is the the proof in this image), the binary file may be directly represented using *DocumentReference* and referenced by `derivedFrom`.
- The usage of valueReference is restricted to the MolecularSequence resource when used as a definitional resource, not as a patient-specific finding. .
- For additional guidance, see the [Notes section](https://hl7.org/fhir/observ.html#notes) below."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="Extension"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <isModifier value="false"/>
    </element>
    <element id="Extension.url">
      <path value="Extension.url"/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="Extension.url"/>
        <min value="1"/>
        <max value="1"/>
      </base>
      <fixedUri
                value="http://hl7.org/fhir/5.0/StructureDefinition/extension-Observation.value"/>
    </element>
    <element id="Extension.value[x]">
      <path value="Extension.value[x]"/>
      <short value="Actual result"/>
      <definition
                  value="The information determined as a result of making the observation, if the information has a simple value."/>
      <comment
               value="- An observation may have:
  1.  a single value here
  1.  both a value and a set of related or component values
  1.  only a set of related or component values.
-  If a value is present, the datatype for this element should be determined by the `code`.
-  *CodeableConcept* with just a text would be used instead of a string if the field was usually coded, or if the type associated with the `code` defines a coded value.
-  *Attachment* is used if the observation result value is a binary file such as an image.  If the observation result value is derived from the binary file (for example 'X' detected and here is the the proof in this image), the binary file may be directly represented using *DocumentReference* and referenced by `derivedFrom`.
- The usage of valueReference is restricted to the MolecularSequence resource when used as a definitional resource, not as a patient-specific finding. .
- For additional guidance, see the [Notes section](https://hl7.org/fhir/observ.html#notes) below."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="Extension.value[x]"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="Attachment"/>
      </type>
      <type>
        <code value="Reference"/>
        <targetProfile
                       value="http://hl7.org/fhir/5.0/StructureDefinition/profile-MolecularSequence|0.1.0"/>
        <targetProfile
                       value="http://hl7.org/fhir/StructureDefinition/MolecularSequence|4.0.1"/>
      </type>
    </element>
  </differential>
</StructureDefinition>