Release 5 Ballot

This page is part of the FHIR Specification (v5.0.0-ballot: R5 Ballot - see ballot notes). The current version which supercedes this version is 5.0.0. For a full list of available versions, see the Directory of published versions . Page versions: R5 R4B R4 R3 R2

Example StructureDefinition/Coding (XML)

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

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

StructureDefinition for Coding

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

<StructureDefinition xmlns="http://hl7.org/fhir">
  <id value="Coding"/> 
  <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="formats.html#table" 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="formats.html#table" 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="formats.html#table" 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="formats.html#table" 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="formats.html#table" title="Additional information about the element">Description &amp; Constraints</a> 
            <span style="float: right">
              <a href="formats.html#table" title="Legend for this format">
                <img alt="doco" src="help16.png" 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/LjIAAAAI0lEQVR42u3QIQEAAAACIL/6/4MvTAQOkLYBAAB4kA
          AAANwMad9AqkRjgNAAAAAASUVORK5CYII=)">
            <img alt="." class="hierarchy" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAAWCAYAAAABxvaqAAAACXBIWXMAAAsTAAALEwEAmpw
            YAAAAB3RJTUUH3wYeFzIs1vtcMQAAAB1pVFh0Q29tbWVudAAAAAAAQ3JlYXRlZCB3aXRoIEdJTVBkLmUHAAAAE0lEQVQI1
            2P4//8/AxMDAwNdCABMPwMo2ctnoQAAAABJRU5ErkJggg==" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:image/png;base64,R0lGODlhEAAQAPQfAOvGUf7ztuvPMf/78/fkl/Pbg+u8Rvjqteu2Pf3zxPz36Pz0z+vTmPz
            urPvuw/npofbjquvNefHVduuyN+uuMu3Oafbgjfnqvf/3zv/3xevPi+vRjP/20/bmsP///wD/ACH5BAEKAB8ALAAAAAAQA
            BAAAAVl4CeOZGme5qCqqDg8jyVJaz1876DsmAQAgqDgltspMEhMJoMZ4iy6I1AooFCIv+wKybziALVAoAEjYLwDgGIpJhM
            slgxaLR4/3rMAWoBp32V5exg8Shl1ckRUQVaMVkQ2kCstKCEAOw==" style="background-color: white; background-color: inherit" title="Element"/>  
            <a href="datatypes-definitions.html#Coding" title="Coding : A reference to a code defined by a terminology system.">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">
            <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">A reference to a code defined by a terminology system
            <br/>  
            <span style="font-style: italic" title="cod-1">+ Warning: A Coding SHOULD NOT have a display unless a code is also present.  Computation
               on Coding.display alone is generally unsafe.  Consider using CodeableConcept.text</span> 
            <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 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.">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/LjIAAAAL0lEQVR42u3XsQ0AQAg
          CQHdl/xn8jxvYWB3JlTR0VJLa+OltBwAAYP6EEQAAgCsPVYVAgIJrA/sAAAAASUVORK5CYII=)">
            <img alt="." class="hierarchy" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAAWCAYAAAABxvaqAAAACXBIWXMAAAsTAAALEwEAmpw
            YAAAAB3RJTUUH3wYeFzIs1vtcMQAAAB1pVFh0Q29tbWVudAAAAAAAQ3JlYXRlZCB3aXRoIEdJTVBkLmUHAAAAE0lEQVQI1
            2P4//8/AxMDAwNdCABMPwMo2ctnoQAAAABJRU5ErkJggg==" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAWCAYAAADJqhx8AAAACXBIWXMAAAsTAAALEwEAmpw
            YAAAAB3RJTUUH3wYeFzI3XJ6V3QAAAB1pVFh0Q29tbWVudAAAAAAAQ3JlYXRlZCB3aXRoIEdJTVBkLmUHAAAANklEQVQ4y
            +2RsQ0AIAzDav7/2VzQwoCY4iWbZSmo1QGoUgNMghvWaIejPQW/CrrNCylIwcOCDYfLNRcNer4SAAAAAElFTkSuQmCC" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAACXBIWXMAAAsTAAALEwEAmpw
            YAAAARklEQVQ4y2P8//8/AyWAhYFCMAgMuHjx4n+KXaCv+I0szW8WpCG8kFO1lGFKW/SIjAUYgxz/MzAwMDC+nqhDUTQyj
            uYFBgCNmhP4OvTRgwAAAABJRU5ErkJggg==" style="background-color: #F7F7F7; background-color: inherit" title="Primitive Data Type"/>  
            <a href="datatypes-definitions.html#Coding.system" title="Coding.system : The identification of the code system that defines the meaning
             of the symbol in the code.">system</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">Identity of the terminology system
            <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/LjIAAAAL0lEQVR42u3XsQ0AQAgCQHdl/xn8jxvYWB3JlTR0VJ
          La+OltBwAAYP6EEQAAgCsPVYVAgIJrA/sAAAAASUVORK5CYII=)">
            <img alt="." class="hierarchy" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAAWCAYAAAABxvaqAAAACXBIWXMAAAsTAAALEwEAmpw
            YAAAAB3RJTUUH3wYeFzIs1vtcMQAAAB1pVFh0Q29tbWVudAAAAAAAQ3JlYXRlZCB3aXRoIEdJTVBkLmUHAAAAE0lEQVQI1
            2P4//8/AxMDAwNdCABMPwMo2ctnoQAAAABJRU5ErkJggg==" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAWCAYAAADJqhx8AAAACXBIWXMAAAsTAAALEwEAmpw
            YAAAAB3RJTUUH3wYeFzI3XJ6V3QAAAB1pVFh0Q29tbWVudAAAAAAAQ3JlYXRlZCB3aXRoIEdJTVBkLmUHAAAANklEQVQ4y
            +2RsQ0AIAzDav7/2VzQwoCY4iWbZSmo1QGoUgNMghvWaIejPQW/CrrNCylIwcOCDYfLNRcNer4SAAAAAElFTkSuQmCC" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAACXBIWXMAAAsTAAALEwEAmpw
            YAAAARklEQVQ4y2P8//8/AyWAhYFCMAgMuHjx4n+KXaCv+I0szW8WpCG8kFO1lGFKW/SIjAUYgxz/MzAwMDC+nqhDUTQyj
            uYFBgCNmhP4OvTRgwAAAABJRU5ErkJggg==" style="background-color: white; background-color: inherit" title="Primitive Data Type"/>  
            <a href="datatypes-definitions.html#Coding.version" title="Coding.version : The version of the code system which was used when choosing this
             code. Note that a well-maintained code system does not need the version reported,
             because the meaning of codes is consistent across versions. However this cannot
             consistently be assured, and when the meaning is not guaranteed to be consistent,
             the version SHOULD be exchanged.">version</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#string">string</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">Version of the system - if relevant
            <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/LjIAAAAL0lEQVR42u3XsQ0AQAg
          CQHdl/xn8jxvYWB3JlTR0VJLa+OltBwAAYP6EEQAAgCsPVYVAgIJrA/sAAAAASUVORK5CYII=)">
            <img alt="." class="hierarchy" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAAWCAYAAAABxvaqAAAACXBIWXMAAAsTAAALEwEAmpw
            YAAAAB3RJTUUH3wYeFzIs1vtcMQAAAB1pVFh0Q29tbWVudAAAAAAAQ3JlYXRlZCB3aXRoIEdJTVBkLmUHAAAAE0lEQVQI1
            2P4//8/AxMDAwNdCABMPwMo2ctnoQAAAABJRU5ErkJggg==" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAWCAYAAADJqhx8AAAACXBIWXMAAAsTAAALEwEAmpw
            YAAAAB3RJTUUH3wYeFzI3XJ6V3QAAAB1pVFh0Q29tbWVudAAAAAAAQ3JlYXRlZCB3aXRoIEdJTVBkLmUHAAAANklEQVQ4y
            +2RsQ0AIAzDav7/2VzQwoCY4iWbZSmo1QGoUgNMghvWaIejPQW/CrrNCylIwcOCDYfLNRcNer4SAAAAAElFTkSuQmCC" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAACXBIWXMAAAsTAAALEwEAmpw
            YAAAARklEQVQ4y2P8//8/AyWAhYFCMAgMuHjx4n+KXaCv+I0szW8WpCG8kFO1lGFKW/SIjAUYgxz/MzAwMDC+nqhDUTQyj
            uYFBgCNmhP4OvTRgwAAAABJRU5ErkJggg==" style="background-color: #F7F7F7; background-color: inherit" title="Primitive Data Type"/>  
            <a href="datatypes-definitions.html#Coding.code" title="Coding.code : A symbol in syntax defined by the system. The symbol may be a predefined
             code or an expression in a syntax defined by the coding system (e.g. post-coordination).">code</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#code">code</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px
           #F0F0F0 solid; padding:0px 4px 0px 4px">Symbol in syntax defined by the system
            <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/LjIAAAAL0lEQVR42u3XsQ0AQAgCQHdl/xn8jxvYWB3JlTR0VJ
          La+OltBwAAYP6EEQAAgCsPVYVAgIJrA/sAAAAASUVORK5CYII=)">
            <img alt="." class="hierarchy" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAAWCAYAAAABxvaqAAAACXBIWXMAAAsTAAALEwEAmpw
            YAAAAB3RJTUUH3wYeFzIs1vtcMQAAAB1pVFh0Q29tbWVudAAAAAAAQ3JlYXRlZCB3aXRoIEdJTVBkLmUHAAAAE0lEQVQI1
            2P4//8/AxMDAwNdCABMPwMo2ctnoQAAAABJRU5ErkJggg==" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAWCAYAAADJqhx8AAAACXBIWXMAAAsTAAALEwEAmpw
            YAAAAB3RJTUUH3wYeFzI3XJ6V3QAAAB1pVFh0Q29tbWVudAAAAAAAQ3JlYXRlZCB3aXRoIEdJTVBkLmUHAAAANklEQVQ4y
            +2RsQ0AIAzDav7/2VzQwoCY4iWbZSmo1QGoUgNMghvWaIejPQW/CrrNCylIwcOCDYfLNRcNer4SAAAAAElFTkSuQmCC" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAACXBIWXMAAAsTAAALEwEAmpw
            YAAAARklEQVQ4y2P8//8/AyWAhYFCMAgMuHjx4n+KXaCv+I0szW8WpCG8kFO1lGFKW/SIjAUYgxz/MzAwMDC+nqhDUTQyj
            uYFBgCNmhP4OvTRgwAAAABJRU5ErkJggg==" style="background-color: white; background-color: inherit" title="Primitive Data Type"/>  
            <a href="datatypes-definitions.html#Coding.display" title="Coding.display : A representation of the meaning of the code in the system, following
             the rules of the system.">display</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#string">string</a> 
          </td> 
          <td class="hierarchy" style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0
           solid; padding:0px 4px 0px 4px">Representation defined by the system
            <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/LjIAAAAI0lEQVR42u3QIQEAAAA
          CIL/6/4MvTAQOkLYBAAB4kAAAANwMad9AqkRjgNAAAAAASUVORK5CYII=)">
            <img alt="." class="hierarchy" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAAWCAYAAAABxvaqAAAACXBIWXMAAAsTAAALEwEAmpw
            YAAAAB3RJTUUH3wYeFzIs1vtcMQAAAB1pVFh0Q29tbWVudAAAAAAAQ3JlYXRlZCB3aXRoIEdJTVBkLmUHAAAAE0lEQVQI1
            2P4//8/AxMDAwNdCABMPwMo2ctnoQAAAABJRU5ErkJggg==" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAWCAYAAADJqhx8AAAACXBIWXMAAAsTAAALEwEAmpw
            YAAAAB3RJTUUH3wYeFzME+lXFigAAAB1pVFh0Q29tbWVudAAAAAAAQ3JlYXRlZCB3aXRoIEdJTVBkLmUHAAAANklEQVQ4y
            +3OsRUAIAjEUOL+O8cJABttJM11/x1qZAGqRBEVcNIqdWj1efDqQbb3HwwwwEfABmQUHSPM9dtDAAAAAElFTkSuQmCC" style="background-color: inherit"/> 
            <img alt="." class="hierarchy" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAACXBIWXMAAAsTAAALEwEAmpw
            YAAAARklEQVQ4y2P8//8/AyWAhYFCMAgMuHjx4n+KXaCv+I0szW8WpCG8kFO1lGFKW/SIjAUYgxz/MzAwMDC+nqhDUTQyj
            uYFBgCNmhP4OvTRgwAAAABJRU5ErkJggg==" style="background-color: #F7F7F7; background-color: inherit" title="Primitive Data Type"/>  
            <a href="datatypes-definitions.html#Coding.userSelected" title="Coding.userSelected : Indicates that this coding was chosen by a user directly
             - e.g. off a pick list of available items (codes or displays).">userSelected</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">If this coding was chosen directly by the user
            <br/>  
          </td> 
        </tr> 

        <tr> 
          <td class="hierarchy" colspan="5">
            <br/>  
            <a href="formats.html#table" title="Legend for this format">
              <img alt="doco" src="help16.png" 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/Coding"/> 
  <version value="5.0.0-ballot"/> 
  <name value="Coding"/> 
  <status value="active"/> 
  <experimental value="false"/> 
  <date value="2022-09-10T04:52:37+10:00"/> 
  <publisher value="HL7 FHIR Standard"/> 
  <contact> 
    <telecom> 
      <system value="url"/> 
      <value value="http://hl7.org/fhir"/> 
    </telecom> 
  </contact> 
  <description value="Coding Type: A reference to a code defined by a terminology system."/> 
  <purpose value="References to codes are very common in healthcare models."/> 
  <fhirVersion value="5.0.0-ballot"/> 
  <mapping> 
    <identity value="v2"/> 
    <uri value="http://hl7.org/v2"/> 
    <name value="HL7 v2 Mapping"/> 
  </mapping> 
  <mapping> 
    <identity value="rim"/> 
    <uri value="http://hl7.org/v3"/> 
    <name value="RIM Mapping"/> 
  </mapping> 
  <mapping> 
    <identity value="orim"/> 
    <uri value="http://hl7.org/orim"/> 
    <name value="Ontological RIM Mapping"/> 
  </mapping> 
  <kind value="complex-type"/> 
  <abstract value="false"/> 
  <type value="Coding"/> 
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/DataType"/> 
  <derivation value="specialization"/> 
  <snapshot> 
    <element id="Coding">
      <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="Coding"/> 
      <short value="A reference to a code defined by a terminology system"/> 
      <definition value="A reference to a code defined by a terminology system."/> 
      <comment value="Codes may be defined very casually in enumerations or code lists, up to very formal
       definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="Coding"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <constraint> 
        <key value="cod-1"/> 
        <severity value="warning"/> 
        <human value="A Coding SHOULD NOT have a display unless a code is also present.  Computation
         on Coding.display alone is generally unsafe.  Consider using CodeableConcept.text"/> 
        <expression value="code.exists().not() implies display.exists().not()"/> 
        <xpath value="exists(f:code) or not(exists(f:display))"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Coding"/> 
      </constraint> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="n/a"/> 
      </mapping> 
      <mapping> 
        <identity value="v2"/> 
        <map value="CE/CNE/CWE subset one of the sets of component 1-3 or 4-6"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="CV"/> 
      </mapping> 
      <mapping> 
        <identity value="orim"/> 
        <map value="fhir:Coding rdfs:subClassOf dt:CDCoding"/> 
      </mapping> 
    </element> 
    <element id="Coding.id">
      <path value="Coding.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> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="n/a"/> 
      </mapping> 
    </element> 
    <element id="Coding.extension">
      <path value="Coding.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"/> 
      </constraint> 
      <constraint> 
        <key value="ext-1"/> 
        <severity value="error"/> 
        <human value="Must have either extensions or value[x], not both"/> 
        <expression value="extension.exists() != value.exists()"/> 
        <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="n/a"/> 
      </mapping> 
    </element> 
    <element id="Coding.system">
      <path value="Coding.system"/> 
      <short value="Identity of the terminology system"/> 
      <definition value="The identification of the code system that defines the meaning of the symbol in
       the code."/> 
      <comment value="The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...).  OIDs and UUIDs SHALL
       be references to the HL7 OID registry. Otherwise, the URI should come from HL7's
       list of FHIR defined special URIs or it should be an absolute reference to some
       definition that establishes the system clearly and unambiguously."/> 
      <requirements value="Need to be unambiguous about the source of the definition of the symbol."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Coding.system"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="uri"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="v2"/> 
        <map value="C*E.3"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="./codeSystem"/> 
      </mapping> 
      <mapping> 
        <identity value="orim"/> 
        <map value="fhir:Coding.system rdfs:subPropertyOf dt:CDCoding.codeSystem"/> 
      </mapping> 
    </element> 
    <element id="Coding.version">
      <path value="Coding.version"/> 
      <short value="Version of the system - if relevant"/> 
      <definition value="The version of the code system which was used when choosing this code. Note that
       a well-maintained code system does not need the version reported, because the meaning
       of codes is consistent across versions. However this cannot consistently be assured,
       and when the meaning is not guaranteed to be consistent, the version SHOULD be
       exchanged."/> 
      <comment value="Where the terminology does not clearly define what string should be used to identify
       code system versions, the recommendation is to use the date (expressed in FHIR
       date format) on which that version was officially published as the version date."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Coding.version"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="string"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="v2"/> 
        <map value="C*E.7"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="./codeSystemVersion"/> 
      </mapping> 
      <mapping> 
        <identity value="orim"/> 
        <map value="fhir:Coding.version rdfs:subPropertyOf dt:CDCoding.codeSystemVersion"/> 
      </mapping> 
    </element> 
    <element id="Coding.code">
      <extension url="http://hl7.org/fhir/build/StructureDefinition/no-binding">
        <valueBoolean value="true"/> 
      </extension> 
      <path value="Coding.code"/> 
      <short value="Symbol in syntax defined by the system"/> 
      <definition value="A symbol in syntax defined by the system. The symbol may be a predefined code or
       an expression in a syntax defined by the coding system (e.g. post-coordination)."/> 
      <requirements value="Need to refer to a particular code in the system."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Coding.code"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="code"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="v2"/> 
        <map value="C*E.1"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="./code"/> 
      </mapping> 
      <mapping> 
        <identity value="orim"/> 
        <map value="fhir:Coding.code rdfs:subPropertyOf dt:CDCoding.code"/> 
      </mapping> 
    </element> 
    <element id="Coding.display">
      <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/> 
      </extension> 
      <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/> 
      </extension> 
      <path value="Coding.display"/> 
      <short value="Representation defined by the system"/> 
      <definition value="A representation of the meaning of the code in the system, following the rules
       of the system."/> 
      <requirements value="Need to be able to carry a human-readable meaning of the code for readers that
       do not know  the system."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Coding.display"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="string"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="v2"/> 
        <map value="C*E.2 - but note this is not well followed"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="CV.displayName"/> 
      </mapping> 
      <mapping> 
        <identity value="orim"/> 
        <map value="fhir:Coding.display rdfs:subPropertyOf dt:CDCoding.displayName"/> 
      </mapping> 
    </element> 
    <element id="Coding.userSelected">
      <path value="Coding.userSelected"/> 
      <short value="If this coding was chosen directly by the user"/> 
      <definition value="Indicates that this coding was chosen by a user directly - e.g. off a pick list
       of available items (codes or displays)."/> 
      <comment value="Amongst a set of alternatives, a directly chosen code is the most appropriate starting
       point for new translations. There is some ambiguity about what exactly 'directly
       chosen' implies, and trading partner agreement may be needed to clarify the use
       of this element and its consequences more completely."/> 
      <requirements value="This has been identified as a clinical safety criterium - that this exact system/code
       pair was chosen explicitly, rather than inferred by the system based on some rules
       or language processing."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Coding.userSelected"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="boolean"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="v2"/> 
        <map value="Sometimes implied by being first"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="CD.codingRationale"/> 
      </mapping> 
      <mapping> 
        <identity value="orim"/> 
        <map value="fhir:Coding.userSelected fhir:mapsTo dt:CDCoding.codingRationale. fhir:Coding.userSelected
         fhir:hasMap fhir:Coding.userSelected.map. fhir:Coding.userSelected.map a fhir:Map;
           fhir:target dt:CDCoding.codingRationale. fhir:Coding.userSelected\#true a [ 
            fhir:source &quot;true&quot;;     fhir:target dt:CDCoding.codingRationale\#O
           ]"/> 
      </mapping> 
    </element> 
  </snapshot> 
  <differential> 
    <element id="Coding">
      <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="Coding"/> 
      <short value="A reference to a code defined by a terminology system"/> 
      <definition value="A reference to a code defined by a terminology system."/> 
      <comment value="Codes may be defined very casually in enumerations or code lists, up to very formal
       definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information."/> 
      <min value="0"/> 
      <max value="*"/> 
      <constraint> 
        <key value="cod-1"/> 
        <severity value="warning"/> 
        <human value="A Coding SHOULD NOT have a display unless a code is also present.  Computation
         on Coding.display alone is generally unsafe.  Consider using CodeableConcept.text"/> 
        <expression value="code.exists().not() implies display.exists().not()"/> 
        <xpath value="exists(f:code) or not(exists(f:display))"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Coding"/> 
      </constraint> 
      <mapping> 
        <identity value="v2"/> 
        <map value="CE/CNE/CWE subset one of the sets of component 1-3 or 4-6"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="CV"/> 
      </mapping> 
      <mapping> 
        <identity value="orim"/> 
        <map value="fhir:Coding rdfs:subClassOf dt:CDCoding"/> 
      </mapping> 
    </element> 
    <element id="Coding.system">
      <path value="Coding.system"/> 
      <short value="Identity of the terminology system"/> 
      <definition value="The identification of the code system that defines the meaning of the symbol in
       the code."/> 
      <comment value="The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...).  OIDs and UUIDs SHALL
       be references to the HL7 OID registry. Otherwise, the URI should come from HL7's
       list of FHIR defined special URIs or it should be an absolute reference to some
       definition that establishes the system clearly and unambiguously."/> 
      <requirements value="Need to be unambiguous about the source of the definition of the symbol."/> 
      <min value="0"/> 
      <max value="1"/> 
      <type> 
        <code value="uri"/> 
      </type> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="v2"/> 
        <map value="C*E.3"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="./codeSystem"/> 
      </mapping> 
      <mapping> 
        <identity value="orim"/> 
        <map value="fhir:Coding.system rdfs:subPropertyOf dt:CDCoding.codeSystem"/> 
      </mapping> 
    </element> 
    <element id="Coding.version">
      <path value="Coding.version"/> 
      <short value="Version of the system - if relevant"/> 
      <definition value="The version of the code system which was used when choosing this code. Note that
       a well-maintained code system does not need the version reported, because the meaning
       of codes is consistent across versions. However this cannot consistently be assured,
       and when the meaning is not guaranteed to be consistent, the version SHOULD be
       exchanged."/> 
      <comment value="Where the terminology does not clearly define what string should be used to identify
       code system versions, the recommendation is to use the date (expressed in FHIR
       date format) on which that version was officially published as the version date."/> 
      <min value="0"/> 
      <max value="1"/> 
      <type> 
        <code value="string"/> 
      </type> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="v2"/> 
        <map value="C*E.7"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="./codeSystemVersion"/> 
      </mapping> 
      <mapping> 
        <identity value="orim"/> 
        <map value="fhir:Coding.version rdfs:subPropertyOf dt:CDCoding.codeSystemVersion"/> 
      </mapping> 
    </element> 
    <element id="Coding.code">
      <extension url="http://hl7.org/fhir/build/StructureDefinition/no-binding">
        <valueBoolean value="true"/> 
      </extension> 
      <path value="Coding.code"/> 
      <short value="Symbol in syntax defined by the system"/> 
      <definition value="A symbol in syntax defined by the system. The symbol may be a predefined code or
       an expression in a syntax defined by the coding system (e.g. post-coordination)."/> 
      <requirements value="Need to refer to a particular code in the system."/> 
      <min value="0"/> 
      <max value="1"/> 
      <type> 
        <code value="code"/> 
      </type> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="v2"/> 
        <map value="C*E.1"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="./code"/> 
      </mapping> 
      <mapping> 
        <identity value="orim"/> 
        <map value="fhir:Coding.code rdfs:subPropertyOf dt:CDCoding.code"/> 
      </mapping> 
    </element> 
    <element id="Coding.display">
      <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/> 
      </extension> 
      <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/> 
      </extension> 
      <path value="Coding.display"/> 
      <short value="Representation defined by the system"/> 
      <definition value="A representation of the meaning of the code in the system, following the rules
       of the system."/> 
      <requirements value="Need to be able to carry a human-readable meaning of the code for readers that
       do not know  the system."/> 
      <min value="0"/> 
      <max value="1"/> 
      <type> 
        <code value="string"/> 
      </type> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="v2"/> 
        <map value="C*E.2 - but note this is not well followed"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="CV.displayName"/> 
      </mapping> 
      <mapping> 
        <identity value="orim"/> 
        <map value="fhir:Coding.display rdfs:subPropertyOf dt:CDCoding.displayName"/> 
      </mapping> 
    </element> 
    <element id="Coding.userSelected">
      <path value="Coding.userSelected"/> 
      <short value="If this coding was chosen directly by the user"/> 
      <definition value="Indicates that this coding was chosen by a user directly - e.g. off a pick list
       of available items (codes or displays)."/> 
      <comment value="Amongst a set of alternatives, a directly chosen code is the most appropriate starting
       point for new translations. There is some ambiguity about what exactly 'directly
       chosen' implies, and trading partner agreement may be needed to clarify the use
       of this element and its consequences more completely."/> 
      <requirements value="This has been identified as a clinical safety criterium - that this exact system/code
       pair was chosen explicitly, rather than inferred by the system based on some rules
       or language processing."/> 
      <min value="0"/> 
      <max value="1"/> 
      <type> 
        <code value="boolean"/> 
      </type> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="v2"/> 
        <map value="Sometimes implied by being first"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="CD.codingRationale"/> 
      </mapping> 
      <mapping> 
        <identity value="orim"/> 
        <map value="fhir:Coding.userSelected fhir:mapsTo dt:CDCoding.codingRationale. fhir:Coding.userSelected
         fhir:hasMap fhir:Coding.userSelected.map. fhir:Coding.userSelected.map a fhir:Map;
           fhir:target dt:CDCoding.codingRationale. fhir:Coding.userSelected\#true a [ 
            fhir:source &quot;true&quot;;     fhir:target dt:CDCoding.codingRationale\#O
           ]"/> 
      </mapping> 
    </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.