Codesystem-data-types.xml

Definition for Code System DataType

<CodeSystem xmlns="http://hl7.org/fhir">
  <id value="data-types"/>
  <meta>
    <lastUpdated value="2016-12-06T12:22:34.981+11:00"/>
  </meta>
  <text>
    <status value="extensions"/>
    <div xmlns="http://www.w3.org/1999/xhtml">
      <h2>DataType</h2>
      <div>
        <p>The type of an element - one of the FHIR data types.</p>

      </div>
      <p>This code system http://hl7.org/fhir/data-types defines the following codes:</p>
      <table class="codes">
        <tr>
          <td>
            <b>Code</b>
          </td>
          <td>
            <b>Display</b>
          </td>
          <td>
            <b>Definition</b>
          </td>
          <td>
            <b>Comments</b>
          </td>
        </tr>
        <tr>
          <td>Address
            <a name="data-types-Address"> </a>
          </td>
          <td>Address</td>
          <td>An address expressed using postal conventions (as opposed to GPS or other location definition
             formats).  This data type may be used to convey addresses for use in delivering mail as
             well as for visiting locations and which might not be valid for mail delivery.  There
             are a variety of postal address formats defined around the world.</td>
          <td/>
        </tr>
        <tr>
          <td>Age
            <a name="data-types-Age"> </a>
          </td>
          <td>Age</td>
          <td>A duration of time during which an organism (or a process) has existed.</td>
          <td/>
        </tr>
        <tr>
          <td>Annotation
            <a name="data-types-Annotation"> </a>
          </td>
          <td>Annotation</td>
          <td>A  text note which also  contains information about who made the statement and when.</td>
          <td/>
        </tr>
        <tr>
          <td>Attachment
            <a name="data-types-Attachment"> </a>
          </td>
          <td>Attachment</td>
          <td>For referring to data content defined in other formats.</td>
          <td/>
        </tr>
        <tr>
          <td>BackboneElement
            <a name="data-types-BackboneElement"> </a>
          </td>
          <td>BackboneElement</td>
          <td>Base definition for all elements that are defined inside a resource - but not those in
             a data type.</td>
          <td/>
        </tr>
        <tr>
          <td>CodeableConcept
            <a name="data-types-CodeableConcept"> </a>
          </td>
          <td>CodeableConcept</td>
          <td>A concept that may be defined by a formal reference to a terminology or ontology or may
             be provided by text.</td>
          <td/>
        </tr>
        <tr>
          <td>Coding
            <a name="data-types-Coding"> </a>
          </td>
          <td>Coding</td>
          <td>A reference to a code defined by a terminology system.</td>
          <td/>
        </tr>
        <tr>
          <td>ContactDetail
            <a name="data-types-ContactDetail"> </a>
          </td>
          <td>ContactDetail</td>
          <td>Specifies contact information for a person or organization.</td>
          <td/>
        </tr>
        <tr>
          <td>ContactPoint
            <a name="data-types-ContactPoint"> </a>
          </td>
          <td>ContactPoint</td>
          <td>Details for all kinds of technology mediated contact points for a person or organization,
             including telephone, email, etc.</td>
          <td/>
        </tr>
        <tr>
          <td>Contributor
            <a name="data-types-Contributor"> </a>
          </td>
          <td>Contributor</td>
          <td>A contributor to the content of a knowledge asset, including authors, editors, reviewers,
             and endorsers.</td>
          <td/>
        </tr>
        <tr>
          <td>Count
            <a name="data-types-Count"> </a>
          </td>
          <td>Count</td>
          <td>A measured amount (or an amount that can potentially be measured). Note that measured
             amounts include amounts that are not precisely quantified, including amounts involving
             arbitrary units and floating currencies.</td>
          <td/>
        </tr>
        <tr>
          <td>DataRequirement
            <a name="data-types-DataRequirement"> </a>
          </td>
          <td>DataRequirement</td>
          <td>Describes a required data item for evaluation in terms of the type of data, and optional
             code- or date-based filters of the data.</td>
          <td/>
        </tr>
        <tr>
          <td>Distance
            <a name="data-types-Distance"> </a>
          </td>
          <td>Distance</td>
          <td>A length - a value with a unit that is a physical distance.</td>
          <td/>
        </tr>
        <tr>
          <td>DosageInstruction
            <a name="data-types-DosageInstruction"> </a>
          </td>
          <td>DosageInstruction</td>
          <td>Indicates how the medication is to be used by the patient.</td>
          <td/>
        </tr>
        <tr>
          <td>Duration
            <a name="data-types-Duration"> </a>
          </td>
          <td>Duration</td>
          <td>A length of time.</td>
          <td/>
        </tr>
        <tr>
          <td>Element
            <a name="data-types-Element"> </a>
          </td>
          <td>Element</td>
          <td>Base definition for all elements in a resource.</td>
          <td/>
        </tr>
        <tr>
          <td>ElementDefinition
            <a name="data-types-ElementDefinition"> </a>
          </td>
          <td>ElementDefinition</td>
          <td>Captures constraints on each element within the resource, profile, or extension.</td>
          <td/>
        </tr>
        <tr>
          <td>Extension
            <a name="data-types-Extension"> </a>
          </td>
          <td>Extension</td>
          <td>Optional Extensions Element - found in all resources.</td>
          <td/>
        </tr>
        <tr>
          <td>HumanName
            <a name="data-types-HumanName"> </a>
          </td>
          <td>HumanName</td>
          <td>A human's name with the ability to identify parts and usage.</td>
          <td/>
        </tr>
        <tr>
          <td>Identifier
            <a name="data-types-Identifier"> </a>
          </td>
          <td>Identifier</td>
          <td>A technical identifier - identifies some entity uniquely and unambiguously.</td>
          <td/>
        </tr>
        <tr>
          <td>Meta
            <a name="data-types-Meta"> </a>
          </td>
          <td>Meta</td>
          <td>The metadata about a resource. This is content in the resource that is maintained by the
             infrastructure. Changes to the content may not always be associated with version changes
             to the resource.</td>
          <td/>
        </tr>
        <tr>
          <td>Money
            <a name="data-types-Money"> </a>
          </td>
          <td>Money</td>
          <td>An amount of economic utility in some recognised currency.</td>
          <td/>
        </tr>
        <tr>
          <td>Narrative
            <a name="data-types-Narrative"> </a>
          </td>
          <td>Narrative</td>
          <td>A human-readable formatted text, including images.</td>
          <td/>
        </tr>
        <tr>
          <td>ParameterDefinition
            <a name="data-types-ParameterDefinition"> </a>
          </td>
          <td>ParameterDefinition</td>
          <td>The parameters to the module. This collection specifies both the input and output parameters.
             Input parameters are provided by the caller as part of the $evaluate operation. Output
             parameters are included in the GuidanceResponse.</td>
          <td/>
        </tr>
        <tr>
          <td>Period
            <a name="data-types-Period"> </a>
          </td>
          <td>Period</td>
          <td>A time period defined by a start and end date and optionally time.</td>
          <td/>
        </tr>
        <tr>
          <td>Quantity
            <a name="data-types-Quantity"> </a>
          </td>
          <td>Quantity</td>
          <td>A measured amount (or an amount that can potentially be measured). Note that measured
             amounts include amounts that are not precisely quantified, including amounts involving
             arbitrary units and floating currencies.</td>
          <td/>
        </tr>
        <tr>
          <td>Range
            <a name="data-types-Range"> </a>
          </td>
          <td>Range</td>
          <td>A set of ordered Quantities defined by a low and high limit.</td>
          <td/>
        </tr>
        <tr>
          <td>Ratio
            <a name="data-types-Ratio"> </a>
          </td>
          <td>Ratio</td>
          <td>A relationship of two Quantity values - expressed as a numerator and a denominator.</td>
          <td/>
        </tr>
        <tr>
          <td>Reference
            <a name="data-types-Reference"> </a>
          </td>
          <td>Reference</td>
          <td>A reference from one resource to another.</td>
          <td/>
        </tr>
        <tr>
          <td>RelatedArtifact
            <a name="data-types-RelatedArtifact"> </a>
          </td>
          <td>RelatedArtifact</td>
          <td>Related artifacts such as additional documentation, justification, or bibliographic references.</td>
          <td/>
        </tr>
        <tr>
          <td>SampledData
            <a name="data-types-SampledData"> </a>
          </td>
          <td>SampledData</td>
          <td>A series of measurements taken by a device, with upper and lower limits. There may be
             more than one dimension in the data.</td>
          <td/>
        </tr>
        <tr>
          <td>Signature
            <a name="data-types-Signature"> </a>
          </td>
          <td>Signature</td>
          <td>A digital signature along with supporting context. The signature may be electronic/cryptographic
             in nature, or a graphical image representing a hand-written signature, or a signature
             process. Different Signature approaches have different utilities.</td>
          <td/>
        </tr>
        <tr>
          <td>SimpleQuantity
            <a name="data-types-SimpleQuantity"> </a>
          </td>
          <td>SimpleQuantity</td>
          <td/>
          <td/>
        </tr>
        <tr>
          <td>Timing
            <a name="data-types-Timing"> </a>
          </td>
          <td>Timing</td>
          <td>Specifies an event that may occur multiple times. Timing schedules are used to record
             when things are expected or requested to occur. The most common usage is in dosage instructions
             for medications. They are also used when planning care of various kinds.</td>
          <td/>
        </tr>
        <tr>
          <td>TriggerDefinition
            <a name="data-types-TriggerDefinition"> </a>
          </td>
          <td>TriggerDefinition</td>
          <td>A description of a triggering event.</td>
          <td/>
        </tr>
        <tr>
          <td>UsageContext
            <a name="data-types-UsageContext"> </a>
          </td>
          <td>UsageContext</td>
          <td>Specifies clinical/business/etc metadata that can be used to retrieve, index and/or categorize
             an artifact. This metadata can either be specific to the applicable population (e.g.,
             age category, DRG) or the specific context of care (e.g., venue, care setting, provider
             of care).</td>
          <td/>
        </tr>
        <tr>
          <td>base64Binary
            <a name="data-types-base64Binary"> </a>
          </td>
          <td>base64Binary</td>
          <td>A stream of bytes</td>
          <td/>
        </tr>
        <tr>
          <td>boolean
            <a name="data-types-boolean"> </a>
          </td>
          <td>boolean</td>
          <td>Value of &quot;true&quot; or &quot;false&quot;</td>
          <td/>
        </tr>
        <tr>
          <td>code
            <a name="data-types-code"> </a>
          </td>
          <td>code</td>
          <td>A string which has at least one character and no leading or trailing whitespace and where
             there is no whitespace other than single spaces in the contents</td>
          <td/>
        </tr>
        <tr>
          <td>date
            <a name="data-types-date"> </a>
          </td>
          <td>date</td>
          <td>A date or partial date (e.g. just year or year + month). There is no time zone. The format
             is a union of the schema types gYear, gYearMonth and date.  Dates SHALL be valid dates.</td>
          <td/>
        </tr>
        <tr>
          <td>dateTime
            <a name="data-types-dateTime"> </a>
          </td>
          <td>dateTime</td>
          <td>A date, date-time or partial date (e.g. just year or year + month).  If hours and minutes
             are specified, a time zone SHALL be populated. The format is a union of the schema types
             gYear, gYearMonth, date and dateTime. Seconds must be provided due to schema type constraints
             but may be zero-filled and may be ignored.                 Dates SHALL be valid dates.</td>
          <td/>
        </tr>
        <tr>
          <td>decimal
            <a name="data-types-decimal"> </a>
          </td>
          <td>decimal</td>
          <td>A rational number with implicit precision</td>
          <td/>
        </tr>
        <tr>
          <td>id
            <a name="data-types-id"> </a>
          </td>
          <td>id</td>
          <td>Any combination of letters, numerals, &quot;-&quot; and &quot;.&quot;, with a length limit
             of 64 characters.  (This might be an integer, an unprefixed OID, UUID or any other identifier
             pattern that meets these constraints.)  Ids are case-insensitive.</td>
          <td/>
        </tr>
        <tr>
          <td>instant
            <a name="data-types-instant"> </a>
          </td>
          <td>instant</td>
          <td>An instant in time - known at least to the second</td>
          <td/>
        </tr>
        <tr>
          <td>integer
            <a name="data-types-integer"> </a>
          </td>
          <td>integer</td>
          <td>A whole number</td>
          <td/>
        </tr>
        <tr>
          <td>markdown
            <a name="data-types-markdown"> </a>
          </td>
          <td>markdown</td>
          <td>A string that may contain markdown syntax for optional processing by a mark down presentation
             engine</td>
          <td/>
        </tr>
        <tr>
          <td>oid
            <a name="data-types-oid"> </a>
          </td>
          <td>oid</td>
          <td>An oid represented as a URI</td>
          <td/>
        </tr>
        <tr>
          <td>positiveInt
            <a name="data-types-positiveInt"> </a>
          </td>
          <td>positiveInt</td>
          <td>An integer with a value that is positive (e.g. &gt;0)</td>
          <td/>
        </tr>
        <tr>
          <td>string
            <a name="data-types-string"> </a>
          </td>
          <td>string</td>
          <td>A sequence of Unicode characters</td>
          <td/>
        </tr>
        <tr>
          <td>time
            <a name="data-types-time"> </a>
          </td>
          <td>time</td>
          <td>A time during the day, with no date specified</td>
          <td/>
        </tr>
        <tr>
          <td>unsignedInt
            <a name="data-types-unsignedInt"> </a>
          </td>
          <td>unsignedInt</td>
          <td>An integer with a value that is not negative (e.g. &gt;= 0)</td>
          <td/>
        </tr>
        <tr>
          <td>uri
            <a name="data-types-uri"> </a>
          </td>
          <td>uri</td>
          <td>String of characters used to identify a name or a resource</td>
          <td/>
        </tr>
        <tr>
          <td>uuid
            <a name="data-types-uuid"> </a>
          </td>
          <td>uuid</td>
          <td>A UUID, represented as a URI</td>
          <td/>
        </tr>
        <tr>
          <td>xhtml
            <a name="data-types-xhtml"> </a>
          </td>
          <td>XHTML</td>
          <td>XHTML format, as defined by W3C, but restricted usage (mainly, no active content)</td>
          <td>Special case: xhtml can only be used in the narrative Data Type</td>
        </tr>
      </table>
    </div>
  </text>
  <url value="http://hl7.org/fhir/data-types"/>
  <version value="1.8.0"/>
  <name value="DataType"/>
  <status value="draft"/>
  <experimental value="false"/>
  <publisher value="HL7 (FHIR Project)"/>
  <contact>
    <telecom>
      <system value="url"/>
      <value value="http://hl7.org/fhir"/>
    </telecom>
    <telecom>
      <system value="email"/>
      <value value="fhir@lists.hl7.org"/>
    </telecom>
  </contact>
  <date value="2016-12-06T12:22:34+11:00"/>
  <description value="The type of an element - one of the FHIR data types."/>
  <caseSensitive value="true"/>
  <valueSet value="http://hl7.org/fhir/ValueSet/data-types"/>
  <content value="complete"/>
  <concept>
    <code value="Address"/>
    <display value="Address"/>
    <definition value="An address expressed using postal conventions (as opposed to GPS or other location definition
     formats).  This data type may be used to convey addresses for use in delivering mail as
     well as for visiting locations and which might not be valid for mail delivery.  There
     are a variety of postal address formats defined around the world."/>
  </concept>
  <concept>
    <code value="Age"/>
    <display value="Age"/>
    <definition value="A duration of time during which an organism (or a process) has existed."/>
  </concept>
  <concept>
    <code value="Annotation"/>
    <display value="Annotation"/>
    <definition value="A  text note which also  contains information about who made the statement and when."/>
  </concept>
  <concept>
    <code value="Attachment"/>
    <display value="Attachment"/>
    <definition value="For referring to data content defined in other formats."/>
  </concept>
  <concept>
    <code value="BackboneElement"/>
    <display value="BackboneElement"/>
    <definition value="Base definition for all elements that are defined inside a resource - but not those in
     a data type."/>
  </concept>
  <concept>
    <code value="CodeableConcept"/>
    <display value="CodeableConcept"/>
    <definition value="A concept that may be defined by a formal reference to a terminology or ontology or may
     be provided by text."/>
  </concept>
  <concept>
    <code value="Coding"/>
    <display value="Coding"/>
    <definition value="A reference to a code defined by a terminology system."/>
  </concept>
  <concept>
    <code value="ContactDetail"/>
    <display value="ContactDetail"/>
    <definition value="Specifies contact information for a person or organization."/>
  </concept>
  <concept>
    <code value="ContactPoint"/>
    <display value="ContactPoint"/>
    <definition value="Details for all kinds of technology mediated contact points for a person or organization,
     including telephone, email, etc."/>
  </concept>
  <concept>
    <code value="Contributor"/>
    <display value="Contributor"/>
    <definition value="A contributor to the content of a knowledge asset, including authors, editors, reviewers,
     and endorsers."/>
  </concept>
  <concept>
    <code value="Count"/>
    <display value="Count"/>
    <definition value="A measured amount (or an amount that can potentially be measured). Note that measured
     amounts include amounts that are not precisely quantified, including amounts involving
     arbitrary units and floating currencies."/>
  </concept>
  <concept>
    <code value="DataRequirement"/>
    <display value="DataRequirement"/>
    <definition value="Describes a required data item for evaluation in terms of the type of data, and optional
     code- or date-based filters of the data."/>
  </concept>
  <concept>
    <code value="Distance"/>
    <display value="Distance"/>
    <definition value="A length - a value with a unit that is a physical distance."/>
  </concept>
  <concept>
    <code value="DosageInstruction"/>
    <display value="DosageInstruction"/>
    <definition value="Indicates how the medication is to be used by the patient."/>
  </concept>
  <concept>
    <code value="Duration"/>
    <display value="Duration"/>
    <definition value="A length of time."/>
  </concept>
  <concept>
    <code value="Element"/>
    <display value="Element"/>
    <definition value="Base definition for all elements in a resource."/>
  </concept>
  <concept>
    <code value="ElementDefinition"/>
    <display value="ElementDefinition"/>
    <definition value="Captures constraints on each element within the resource, profile, or extension."/>
  </concept>
  <concept>
    <code value="Extension"/>
    <display value="Extension"/>
    <definition value="Optional Extensions Element - found in all resources."/>
  </concept>
  <concept>
    <code value="HumanName"/>
    <display value="HumanName"/>
    <definition value="A human's name with the ability to identify parts and usage."/>
  </concept>
  <concept>
    <code value="Identifier"/>
    <display value="Identifier"/>
    <definition value="A technical identifier - identifies some entity uniquely and unambiguously."/>
  </concept>
  <concept>
    <code value="Meta"/>
    <display value="Meta"/>
    <definition value="The metadata about a resource. This is content in the resource that is maintained by the
     infrastructure. Changes to the content may not always be associated with version changes
     to the resource."/>
  </concept>
  <concept>
    <code value="Money"/>
    <display value="Money"/>
    <definition value="An amount of economic utility in some recognised currency."/>
  </concept>
  <concept>
    <code value="Narrative"/>
    <display value="Narrative"/>
    <definition value="A human-readable formatted text, including images."/>
  </concept>
  <concept>
    <code value="ParameterDefinition"/>
    <display value="ParameterDefinition"/>
    <definition value="The parameters to the module. This collection specifies both the input and output parameters.
     Input parameters are provided by the caller as part of the $evaluate operation. Output
     parameters are included in the GuidanceResponse."/>
  </concept>
  <concept>
    <code value="Period"/>
    <display value="Period"/>
    <definition value="A time period defined by a start and end date and optionally time."/>
  </concept>
  <concept>
    <code value="Quantity"/>
    <display value="Quantity"/>
    <definition value="A measured amount (or an amount that can potentially be measured). Note that measured
     amounts include amounts that are not precisely quantified, including amounts involving
     arbitrary units and floating currencies."/>
  </concept>
  <concept>
    <code value="Range"/>
    <display value="Range"/>
    <definition value="A set of ordered Quantities defined by a low and high limit."/>
  </concept>
  <concept>
    <code value="Ratio"/>
    <display value="Ratio"/>
    <definition value="A relationship of two Quantity values - expressed as a numerator and a denominator."/>
  </concept>
  <concept>
    <code value="Reference"/>
    <display value="Reference"/>
    <definition value="A reference from one resource to another."/>
  </concept>
  <concept>
    <code value="RelatedArtifact"/>
    <display value="RelatedArtifact"/>
    <definition value="Related artifacts such as additional documentation, justification, or bibliographic references."/>
  </concept>
  <concept>
    <code value="SampledData"/>
    <display value="SampledData"/>
    <definition value="A series of measurements taken by a device, with upper and lower limits. There may be
     more than one dimension in the data."/>
  </concept>
  <concept>
    <code value="Signature"/>
    <display value="Signature"/>
    <definition value="A digital signature along with supporting context. The signature may be electronic/cryptographic
     in nature, or a graphical image representing a hand-written signature, or a signature
     process. Different Signature approaches have different utilities."/>
  </concept>
  <concept>
    <code value="SimpleQuantity"/>
    <display value="SimpleQuantity"/>
  </concept>
  <concept>
    <code value="Timing"/>
    <display value="Timing"/>
    <definition value="Specifies an event that may occur multiple times. Timing schedules are used to record
     when things are expected or requested to occur. The most common usage is in dosage instructions
     for medications. They are also used when planning care of various kinds."/>
  </concept>
  <concept>
    <code value="TriggerDefinition"/>
    <display value="TriggerDefinition"/>
    <definition value="A description of a triggering event."/>
  </concept>
  <concept>
    <code value="UsageContext"/>
    <display value="UsageContext"/>
    <definition value="Specifies clinical/business/etc metadata that can be used to retrieve, index and/or categorize
     an artifact. This metadata can either be specific to the applicable population (e.g.,
     age category, DRG) or the specific context of care (e.g., venue, care setting, provider
     of care)."/>
  </concept>
  <concept>
    <code value="base64Binary"/>
    <display value="base64Binary"/>
    <definition value="A stream of bytes"/>
  </concept>
  <concept>
    <code value="boolean"/>
    <display value="boolean"/>
    <definition value="Value of &quot;true&quot; or &quot;false&quot;"/>
  </concept>
  <concept>
    <code value="code"/>
    <display value="code"/>
    <definition value="A string which has at least one character and no leading or trailing whitespace and where
     there is no whitespace other than single spaces in the contents"/>
  </concept>
  <concept>
    <code value="date"/>
    <display value="date"/>
    <definition value="A date or partial date (e.g. just year or year + month). There is no time zone. The format
     is a union of the schema types gYear, gYearMonth and date.  Dates SHALL be valid dates."/>
  </concept>
  <concept>
    <code value="dateTime"/>
    <display value="dateTime"/>
    <definition value="A date, date-time or partial date (e.g. just year or year + month).  If hours and minutes
     are specified, a time zone SHALL be populated. The format is a union of the schema types
     gYear, gYearMonth, date and dateTime. Seconds must be provided due to schema type constraints
     but may be zero-filled and may be ignored.                 Dates SHALL be valid dates."/>
  </concept>
  <concept>
    <code value="decimal"/>
    <display value="decimal"/>
    <definition value="A rational number with implicit precision"/>
  </concept>
  <concept>
    <code value="id"/>
    <display value="id"/>
    <definition value="Any combination of letters, numerals, &quot;-&quot; and &quot;.&quot;, with a length limit
     of 64 characters.  (This might be an integer, an unprefixed OID, UUID or any other identifier
     pattern that meets these constraints.)  Ids are case-insensitive."/>
  </concept>
  <concept>
    <code value="instant"/>
    <display value="instant"/>
    <definition value="An instant in time - known at least to the second"/>
  </concept>
  <concept>
    <code value="integer"/>
    <display value="integer"/>
    <definition value="A whole number"/>
  </concept>
  <concept>
    <code value="markdown"/>
    <display value="markdown"/>
    <definition value="A string that may contain markdown syntax for optional processing by a mark down presentation
     engine"/>
  </concept>
  <concept>
    <code value="oid"/>
    <display value="oid"/>
    <definition value="An oid represented as a URI"/>
  </concept>
  <concept>
    <code value="positiveInt"/>
    <display value="positiveInt"/>
    <definition value="An integer with a value that is positive (e.g. &gt;0)"/>
  </concept>
  <concept>
    <code value="string"/>
    <display value="string"/>
    <definition value="A sequence of Unicode characters"/>
  </concept>
  <concept>
    <code value="time"/>
    <display value="time"/>
    <definition value="A time during the day, with no date specified"/>
  </concept>
  <concept>
    <code value="unsignedInt"/>
    <display value="unsignedInt"/>
    <definition value="An integer with a value that is not negative (e.g. &gt;= 0)"/>
  </concept>
  <concept>
    <code value="uri"/>
    <display value="uri"/>
    <definition value="String of characters used to identify a name or a resource"/>
  </concept>
  <concept>
    <code value="uuid"/>
    <display value="uuid"/>
    <definition value="A UUID, represented as a URI"/>
  </concept>
  <concept>
    <extension url="http://hl7.org/fhir/StructureDefinition/valueset-comments">
      <valueString value="Special case: xhtml can only be used in the narrative Data Type"/>
    </extension>
    <code value="xhtml"/>
    <display value="XHTML"/>
    <definition value="XHTML format, as defined by W3C, but restricted usage (mainly, no active content)"/>
  </concept>
</CodeSystem>