FHIR Extensions Pack
5.3.0-ballot-tc1 - (September 2025 Ballot) International flag

This page is part of the FHIR Core Extensions Registry (v5.3.0-ballot-tc1: Release 5.3) based on FHIR (HL7® FHIR® Standard) v5.0.0. This version is a pre-release. The current official version is 5.2.0. For a full list of available versions, see the Directory of published versions

Extension: TextLink - Detailed Descriptions

Page standards status: Trial-use Maturity Level: 3

Definitions for the textLink extension.

Guidance on how to interpret the contents of this table can be foundhere

0. Extension
Definition

Link between narrative elements and structured data items in resources


Optional Extension Element - found in all resources.

ShortText LinkOptional Extensions Element
Comments

Used to denote which portions of the narrative are linked to (usually, generated from) structured data in resources. This information might be used in several different ways, including translating and regenerating narrative in applications that are using/presenting the narrative.

Control0..1*
Is Modifierfalse
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
2. Extension.extension
Definition

May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

ShortAdditional content defined by implementations
Comments

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.

Control20..*
TypeExtension
Is Modifierfalse
Summaryfalse
Alternate Namesextensions, user content
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
SlicingThis element introduces a set of slices on Extension.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
  • value @ url
  • 4. Extension.extension:htmlid
    Slice Namehtmlid
    Definition

    The id attribute on an element in the xhtml narrative

    ShortUnique identifierAdditional content defined by implementations
    Comments

    The id attribute on an element in the xhtml narrative.

    Control10..*
    TypeExtension
    Is Modifierfalse
    Summaryfalse
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
    6. Extension.extension:htmlid.extension
    Definition

    An Extension


    May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

    ShortExtensionAdditional content defined by implementations
    Comments

    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.

    Control0..0*
    TypeExtension
    Is Modifierfalse
    Summaryfalse
    Alternate Namesextensions, user content
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
    SlicingThis element introduces a set of slices on Extension.extension.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
    • value @ url
    • 8. Extension.extension:htmlid.url
      Definition

      Source of the definition for the extension code - a logical name or a URL.

      Shortidentifies the meaning of the extension
      Comments

      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.

      Control1..1
      Typeuri
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      XML FormatIn the XML format, this property is represented as an attribute.
      Summaryfalse
      Fixed Valuehtmlid
      10. Extension.extension:htmlid.value[x]
      Definition

      The actual HTML element id


      Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

      ShortValue of extension
      Control10..1
      This element is affected by the following invariants: ext-1
      Typestring, date, Meta, Address, Attachment, integer, Count, DataRequirement, Dosage, uuid, Identifier, RatioRange, Coding, SampledData, id, positiveInt, Distance, Availability, integer64, Period, Duration, canonical, Range, RelatedArtifact, base64Binary, UsageContext, Timing, decimal, ExtendedContactDetail, CodeableConcept, ParameterDefinition, dateTime, code, oid, instant, ContactPoint, HumanName, Money, markdown, Ratio, Age, Reference, TriggerDefinition, Quantity, uri, url, Annotation, ContactDetail, boolean, Expression, CodeableReference, Signature, unsignedInt, time
      [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Summaryfalse
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      12. Extension.extension:data
      Slice Namedata
      Definition

      The id attribute on a resource element (#{id}, relative#{id} or https://absolute#{id})

      ShortUnique identifierAdditional content defined by implementations
      Comments

      The id attribute on an element in the xhtml narrative. The reference can be a fragment to a reference in the resource that contains the narrative, or a relative or absolute URL, optionally with a fragment that identifies an element in the other resource.

      Control10..1*
      TypeExtension
      Is Modifierfalse
      Summaryfalse
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
      14. Extension.extension:data.extension
      Definition

      An Extension


      May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

      ShortExtensionAdditional content defined by implementations
      Comments

      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.

      Control0..0*
      TypeExtension
      Is Modifierfalse
      Summaryfalse
      Alternate Namesextensions, user content
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
      SlicingThis element introduces a set of slices on Extension.extension.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
      • value @ url
      • 16. Extension.extension:data.url
        Definition

        Source of the definition for the extension code - a logical name or a URL.

        Shortidentifies the meaning of the extension
        Comments

        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.

        Control1..1
        Typeuri
        Is Modifierfalse
        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
        XML FormatIn the XML format, this property is represented as an attribute.
        Summaryfalse
        Fixed Valuedata
        18. Extension.extension:data.value[x]
        Definition

        Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

        ShortThe actual data element in this resource, or another resourceValue of extension
        Control10..1
        This element is affected by the following invariants: ext-1
        Typeuri, date, Meta, Address, Attachment, integer, Count, DataRequirement, Dosage, uuid, Identifier, RatioRange, Coding, SampledData, id, positiveInt, Distance, Availability, integer64, Period, Duration, canonical, Range, RelatedArtifact, base64Binary, UsageContext, Timing, decimal, ExtendedContactDetail, CodeableConcept, ParameterDefinition, dateTime, code, string, oid, instant, ContactPoint, HumanName, Money, markdown, Ratio, Age, Reference, TriggerDefinition, Quantity, url, Annotation, ContactDetail, boolean, Expression, CodeableReference, Signature, unsignedInt, time
        [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
        Is Modifierfalse
        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
        Summaryfalse
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        20. Extension.extension:selector
        Slice Nameselector
        Definition

        FHIRPath that selects a subset of the identified data. This sub-extension exists because in some circumstances, the specific data items are in resources where the constructor of the narrative can't introduce specific ids on the relevent elements

        ShortFHIRPath that selects a subset of the identified dataAdditional content defined by implementations
        Control0..1*
        TypeExtension
        Is Modifierfalse
        Summaryfalse
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
        22. Extension.extension:selector.extension
        Definition

        An Extension


        May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

        ShortExtensionAdditional content defined by implementations
        Comments

        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.

        Control0..0*
        TypeExtension
        Is Modifierfalse
        Summaryfalse
        Alternate Namesextensions, user content
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
        SlicingThis element introduces a set of slices on Extension.extension.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
        • value @ url
        • 24. Extension.extension:selector.url
          Definition

          Source of the definition for the extension code - a logical name or a URL.

          Shortidentifies the meaning of the extension
          Comments

          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.

          Control1..1
          Typeuri
          Is Modifierfalse
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          XML FormatIn the XML format, this property is represented as an attribute.
          Summaryfalse
          Fixed Valueselector
          26. Extension.extension:selector.value[x]
          Definition

          Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

          ShortSimple FHIRPath that can't use .resolve()Value of extension
          Control10..1
          This element is affected by the following invariants: ext-1
          Typestring, date, Meta, Address, Attachment, integer, Count, DataRequirement, Dosage, uuid, Identifier, RatioRange, Coding, SampledData, id, positiveInt, Distance, Availability, integer64, Period, Duration, canonical, Range, RelatedArtifact, base64Binary, UsageContext, Timing, decimal, ExtendedContactDetail, CodeableConcept, ParameterDefinition, dateTime, code, oid, instant, ContactPoint, HumanName, Money, markdown, Ratio, Age, Reference, TriggerDefinition, Quantity, uri, url, Annotation, ContactDetail, boolean, Expression, CodeableReference, Signature, unsignedInt, time
          [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
          Is Modifierfalse
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Summaryfalse
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          28. Extension.url
          Definition

          Source of the definition for the extension code - a logical name or a URL.

          Shortidentifies the meaning of the extension
          Comments

          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.

          Control1..1
          Typeuri
          Is Modifierfalse
          XML FormatIn the XML format, this property is represented as an attribute.
          Summaryfalse
          Fixed Valuehttp://hl7.org/fhir/StructureDefinition/textLink
          30. Extension.value[x]
          Definition

          Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

          ShortValue of extension
          Control0..01
          This element is affected by the following invariants: ext-1
          TypeChoice of: base64Binary, boolean, canonical, code, date, dateTime, decimal, id, instant, integer, integer64, markdown, oid, positiveInt, string, time, unsignedInt, uri, url, uuid, Address, Age, Annotation, Attachment, CodeableConcept, CodeableReference, Coding, ContactPoint, Count, Distance, Duration, HumanName, Identifier, Money, Period, Quantity, Range, Ratio, RatioRange, Reference, SampledData, Signature, Timing, ContactDetail, DataRequirement, Expression, ParameterDefinition, RelatedArtifact, TriggerDefinition, UsageContext, Availability, ExtendedContactDetail, Dosage, Meta
          Is Modifierfalse
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Summaryfalse
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))

          Guidance on how to interpret the contents of this table can be foundhere

          0. Extension
          Definition

          Link between narrative elements and structured data items in resources

          ShortText Link
          Comments

          Used to denote which portions of the narrative are linked to (usually, generated from) structured data in resources. This information might be used in several different ways, including translating and regenerating narrative in applications that are using/presenting the narrative.

          Control0..1
          2. Extension.extension:htmlid
          Slice Namehtmlid
          Definition

          The id attribute on an element in the xhtml narrative

          ShortUnique identifier
          Comments

          The id attribute on an element in the xhtml narrative.

          Control1..*
          TypeExtension
          4. Extension.extension:htmlid.extension
          Control0..0
          6. Extension.extension:htmlid.url
          Typeuri
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Fixed Valuehtmlid
          8. Extension.extension:htmlid.value[x]
          Definition

          The actual HTML element id

          Control1..?
          Typestring
          [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          10. Extension.extension:data
          Slice Namedata
          Definition

          The id attribute on a resource element (#{id}, relative#{id} or https://absolute#{id})

          ShortUnique identifier
          Comments

          The id attribute on an element in the xhtml narrative. The reference can be a fragment to a reference in the resource that contains the narrative, or a relative or absolute URL, optionally with a fragment that identifies an element in the other resource.

          Control1..1
          TypeExtension
          12. Extension.extension:data.extension
          Control0..0
          14. Extension.extension:data.url
          Typeuri
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Fixed Valuedata
          16. Extension.extension:data.value[x]
          ShortThe actual data element in this resource, or another resource
          Control1..?
          Typeuri
          [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          18. Extension.extension:selector
          Slice Nameselector
          Definition

          FHIRPath that selects a subset of the identified data. This sub-extension exists because in some circumstances, the specific data items are in resources where the constructor of the narrative can't introduce specific ids on the relevent elements

          ShortFHIRPath that selects a subset of the identified data
          Control0..1
          TypeExtension
          20. Extension.extension:selector.extension
          Control0..0
          22. Extension.extension:selector.url
          Typeuri
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Fixed Valueselector
          24. Extension.extension:selector.value[x]
          ShortSimple FHIRPath that can't use .resolve()
          Control1..?
          Typestring
          [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          26. Extension.url
          Fixed Valuehttp://hl7.org/fhir/StructureDefinition/textLink
          28. Extension.value[x]
          Control0..0

          Guidance on how to interpret the contents of this table can be foundhere

          0. Extension
          Definition

          Link between narrative elements and structured data items in resources

          ShortText Link
          Comments

          Used to denote which portions of the narrative are linked to (usually, generated from) structured data in resources. This information might be used in several different ways, including translating and regenerating narrative in applications that are using/presenting the narrative.

          Control0..1
          Is Modifierfalse
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
          2. Extension.id
          Definition

          Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

          ShortUnique id for inter-element referencing
          Control0..1
          This element is affected by the following invariants: ele-1
          Typeid
          Is Modifierfalse
          XML FormatIn the XML format, this property is represented as an attribute.
          Summaryfalse
          4. Extension.extension
          Definition

          May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

          ShortAdditional content defined by implementations
          Comments

          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.

          Control2..*
          TypeExtension
          Is Modifierfalse
          Summaryfalse
          Alternate Namesextensions, user content
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
          SlicingThis element introduces a set of slices on Extension.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
          • value @ url
          • 6. Extension.extension:htmlid
            Slice Namehtmlid
            Definition

            The id attribute on an element in the xhtml narrative

            ShortUnique identifier
            Comments

            The id attribute on an element in the xhtml narrative.

            Control1..*
            TypeExtension
            Is Modifierfalse
            Summaryfalse
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
            8. Extension.extension:htmlid.id
            Definition

            Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

            ShortUnique id for inter-element referencing
            Control0..1
            This element is affected by the following invariants: ele-1
            Typeid
            Is Modifierfalse
            XML FormatIn the XML format, this property is represented as an attribute.
            Summaryfalse
            10. Extension.extension:htmlid.extension
            Definition

            An Extension

            ShortExtension
            Control0..0
            TypeExtension
            Is Modifierfalse
            Summaryfalse
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
            SlicingThis element introduces a set of slices on Extension.extension.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
            • value @ url
            • 12. Extension.extension:htmlid.url
              Definition

              Source of the definition for the extension code - a logical name or a URL.

              Shortidentifies the meaning of the extension
              Comments

              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.

              Control1..1
              Typeuri
              Is Modifierfalse
              Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
              XML FormatIn the XML format, this property is represented as an attribute.
              Summaryfalse
              Fixed Valuehtmlid
              14. Extension.extension:htmlid.value[x]
              Definition

              The actual HTML element id

              ShortValue of extension
              Control1..1
              This element is affected by the following invariants: ext-1
              Typestring
              [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
              Is Modifierfalse
              Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
              Summaryfalse
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              16. Extension.extension:data
              Slice Namedata
              Definition

              The id attribute on a resource element (#{id}, relative#{id} or https://absolute#{id})

              ShortUnique identifier
              Comments

              The id attribute on an element in the xhtml narrative. The reference can be a fragment to a reference in the resource that contains the narrative, or a relative or absolute URL, optionally with a fragment that identifies an element in the other resource.

              Control1..1
              TypeExtension
              Is Modifierfalse
              Summaryfalse
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
              18. Extension.extension:data.id
              Definition

              Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

              ShortUnique id for inter-element referencing
              Control0..1
              This element is affected by the following invariants: ele-1
              Typeid
              Is Modifierfalse
              XML FormatIn the XML format, this property is represented as an attribute.
              Summaryfalse
              20. Extension.extension:data.extension
              Definition

              An Extension

              ShortExtension
              Control0..0
              TypeExtension
              Is Modifierfalse
              Summaryfalse
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
              SlicingThis element introduces a set of slices on Extension.extension.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
              • value @ url
              • 22. Extension.extension:data.url
                Definition

                Source of the definition for the extension code - a logical name or a URL.

                Shortidentifies the meaning of the extension
                Comments

                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.

                Control1..1
                Typeuri
                Is Modifierfalse
                Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                XML FormatIn the XML format, this property is represented as an attribute.
                Summaryfalse
                Fixed Valuedata
                24. Extension.extension:data.value[x]
                Definition

                Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

                ShortThe actual data element in this resource, or another resource
                Control1..1
                This element is affected by the following invariants: ext-1
                Typeuri
                [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
                Is Modifierfalse
                Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                Summaryfalse
                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                26. Extension.extension:selector
                Slice Nameselector
                Definition

                FHIRPath that selects a subset of the identified data. This sub-extension exists because in some circumstances, the specific data items are in resources where the constructor of the narrative can't introduce specific ids on the relevent elements

                ShortFHIRPath that selects a subset of the identified data
                Control0..1
                TypeExtension
                Is Modifierfalse
                Summaryfalse
                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                28. Extension.extension:selector.id
                Definition

                Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

                ShortUnique id for inter-element referencing
                Control0..1
                This element is affected by the following invariants: ele-1
                Typeid
                Is Modifierfalse
                XML FormatIn the XML format, this property is represented as an attribute.
                Summaryfalse
                30. Extension.extension:selector.extension
                Definition

                An Extension

                ShortExtension
                Control0..0
                TypeExtension
                Is Modifierfalse
                Summaryfalse
                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                SlicingThis element introduces a set of slices on Extension.extension.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
                • value @ url
                • 32. Extension.extension:selector.url
                  Definition

                  Source of the definition for the extension code - a logical name or a URL.

                  Shortidentifies the meaning of the extension
                  Comments

                  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.

                  Control1..1
                  Typeuri
                  Is Modifierfalse
                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                  XML FormatIn the XML format, this property is represented as an attribute.
                  Summaryfalse
                  Fixed Valueselector
                  34. Extension.extension:selector.value[x]
                  Definition

                  Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

                  ShortSimple FHIRPath that can't use .resolve()
                  Control1..1
                  This element is affected by the following invariants: ext-1
                  Typestring
                  [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
                  Is Modifierfalse
                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                  Summaryfalse
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  36. Extension.url
                  Definition

                  Source of the definition for the extension code - a logical name or a URL.

                  Shortidentifies the meaning of the extension
                  Comments

                  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.

                  Control1..1
                  Typeuri
                  Is Modifierfalse
                  XML FormatIn the XML format, this property is represented as an attribute.
                  Summaryfalse
                  Fixed Valuehttp://hl7.org/fhir/StructureDefinition/textLink
                  38. Extension.value[x]
                  Definition

                  Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

                  ShortValue of extension
                  Control0..0
                  This element is affected by the following invariants: ext-1
                  TypeChoice of: base64Binary, boolean, canonical, code, date, dateTime, decimal, id, instant, integer, integer64, markdown, oid, positiveInt, string, time, unsignedInt, uri, url, uuid, Address, Age, Annotation, Attachment, CodeableConcept, CodeableReference, Coding, ContactPoint, Count, Distance, Duration, HumanName, Identifier, Money, Period, Quantity, Range, Ratio, RatioRange, Reference, SampledData, Signature, Timing, ContactDetail, DataRequirement, Expression, ParameterDefinition, RelatedArtifact, TriggerDefinition, UsageContext, Availability, ExtendedContactDetail, Dosage, Meta
                  Is Modifierfalse
                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                  Summaryfalse
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))