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: RelatedRequirement - Detailed Descriptions

Page standards status: Trial-use Maturity Level: 1

Definitions for the cqf-relatedRequirement extension.

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

0. Extension
Definition

Allows relationships to be established between data requirements. For example, a Medication data requirement that depends on a MedicationRequest data requirement.


Optional Extension Element - found in all resources.

ShortExtensionOptional Extensions Element
Control0..*
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.

Control10..*
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:targetId
    Slice NametargetId
    Definition

    The id of a related data requirement (i.e. a data requirement that establishes context for this data requirement)

    ShortWhat data requirementAdditional content defined by implementations
    Comments

    As an example, consider a query for MedicationRequest with all related Medication resources (an include query). In this case the Medication data requirement will specify a relatedDataRequirement of MedicationRequest, with a path of medication.

    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())
    6. Extension.extension:targetId.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 ValuetargetId
    8. Extension.extension:targetId.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..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()))
    10. Extension.extension:targetPath
    Slice NametargetPath
    Definition

    The path to an element in the related data requirement that establishes the relationship. The element is typically of type Reference (or in some cases canonical).

    ShortWhat element establishes the relationshipAdditional content defined by implementations
    Comments

    This element is exclusive with the targetSearchParam element; either the relationship is established by the path to an element, or by a search parameter defining the reference relationship to be followed.

    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())
    12. Extension.extension:targetPath.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 ValuetargetPath
    14. Extension.extension:targetPath.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..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()))
    16. Extension.extension:targetSearchParam
    Slice NametargetSearchParam
    Definition

    The name of a search parameter that establishes the relationship to the related data element.

    ShortWhat search parameter establishes the relationshipAdditional content defined by implementations
    Comments

    This element is exclusive with the targetPath element; either the relationship is established by the path to an element, or by a search parameter defining the reference relationship to be followed.

    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())
    18. Extension.extension:targetSearchParam.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 ValuetargetSearchParam
    20. Extension.extension:targetSearchParam.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..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()))
    22. 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
    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 Valuehttp://hl7.org/fhir/StructureDefinition/cqf-relatedRequirement
    24. 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

    Allows relationships to be established between data requirements. For example, a Medication data requirement that depends on a MedicationRequest data requirement.

    Control0..*
    2. Extension.extension:targetId
    Slice NametargetId
    Definition

    The id of a related data requirement (i.e. a data requirement that establishes context for this data requirement)

    ShortWhat data requirement
    Comments

    As an example, consider a query for MedicationRequest with all related Medication resources (an include query). In this case the Medication data requirement will specify a relatedDataRequirement of MedicationRequest, with a path of medication.

    Control1..1
    TypeExtension
    4. Extension.extension:targetId.url
    Fixed ValuetargetId
    6. Extension.extension:targetId.value[x]
    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
    8. Extension.extension:targetPath
    Slice NametargetPath
    Definition

    The path to an element in the related data requirement that establishes the relationship. The element is typically of type Reference (or in some cases canonical).

    ShortWhat element establishes the relationship
    Comments

    This element is exclusive with the targetSearchParam element; either the relationship is established by the path to an element, or by a search parameter defining the reference relationship to be followed.

    Control0..1
    TypeExtension
    10. Extension.extension:targetPath.url
    Fixed ValuetargetPath
    12. Extension.extension:targetPath.value[x]
    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
    14. Extension.extension:targetSearchParam
    Slice NametargetSearchParam
    Definition

    The name of a search parameter that establishes the relationship to the related data element.

    ShortWhat search parameter establishes the relationship
    Comments

    This element is exclusive with the targetPath element; either the relationship is established by the path to an element, or by a search parameter defining the reference relationship to be followed.

    Control0..1
    TypeExtension
    16. Extension.extension:targetSearchParam.url
    Fixed ValuetargetSearchParam
    18. Extension.extension:targetSearchParam.value[x]
    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
    20. Extension.url
    Typeuri
    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
    Fixed Valuehttp://hl7.org/fhir/StructureDefinition/cqf-relatedRequirement
    22. Extension.value[x]
    Control0..0

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

    0. Extension
    Definition

    Allows relationships to be established between data requirements. For example, a Medication data requirement that depends on a MedicationRequest data requirement.

    ShortExtension
    Control0..*
    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.

    Control1..*
    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:targetId
      Slice NametargetId
      Definition

      The id of a related data requirement (i.e. a data requirement that establishes context for this data requirement)

      ShortWhat data requirement
      Comments

      As an example, consider a query for MedicationRequest with all related Medication resources (an include query). In this case the Medication data requirement will specify a relatedDataRequirement of MedicationRequest, with a path of medication.

      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())
      8. Extension.extension:targetId.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:targetId.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.

      Control0..*
      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
      • 12. Extension.extension:targetId.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 ValuetargetId
        14. Extension.extension:targetId.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..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:targetPath
        Slice NametargetPath
        Definition

        The path to an element in the related data requirement that establishes the relationship. The element is typically of type Reference (or in some cases canonical).

        ShortWhat element establishes the relationship
        Comments

        This element is exclusive with the targetSearchParam element; either the relationship is established by the path to an element, or by a search parameter defining the reference relationship to be followed.

        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())
        18. Extension.extension:targetPath.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:targetPath.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.

        Control0..*
        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
        • 22. Extension.extension:targetPath.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 ValuetargetPath
          24. Extension.extension:targetPath.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..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()))
          26. Extension.extension:targetSearchParam
          Slice NametargetSearchParam
          Definition

          The name of a search parameter that establishes the relationship to the related data element.

          ShortWhat search parameter establishes the relationship
          Comments

          This element is exclusive with the targetPath element; either the relationship is established by the path to an element, or by a search parameter defining the reference relationship to be followed.

          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:targetSearchParam.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:targetSearchParam.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.

          Control0..*
          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
          • 32. Extension.extension:targetSearchParam.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 ValuetargetSearchParam
            34. Extension.extension:targetSearchParam.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..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
            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 Valuehttp://hl7.org/fhir/StructureDefinition/cqf-relatedRequirement
            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()))