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

FHIR Extensions Pack, published by HL7 International / FHIR Infrastructure. This guide is not an authorized publication; it is the continuous build for version 5.3.0-ballot-tc1 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/HL7/fhir-extensions/ and changes regularly. See the Directory of published versions

Extension: MedicationClassification - Detailed Descriptions

Page standards status: Trial-use Maturity Level: 1

Definitions for the medication-classification extension.

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

0. Extension
Definition

Provides a classification for a medication. This allows a Medication resource to carry classification information (e.g., therapeutic class, pharmacologic class) in , including the type of classification system used, one or more classification codes, and an optional source reference.


Optional Extension Element - found in all resources.

ShortMedication ClassificationOptional 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

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.

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:type
    Slice Nametype
    Definition

    Identifies the kind of classification being expressed — that is, the conceptual dimension along which the medication is being grouped. Examples include anatomical class, therapeutic class, pharmacologic class, mechanism of action, chemical-structure class, regulatory classification, controlled-substance schedule, legal or marketing status, reimbursement or formulary class, and public-health lists such as the WHO Essential Medicines List. Note that coding systems such as WHO ATC are not themselves a 'type'; an ATC code expresses an anatomical, therapeutic, pharmacologic, or chemical classification depending on the hierarchy level used. The specific code(s) from such a system are carried in the classification sub-extension.

    ShortThe kind of classification (e.g., anatomical, therapeutic, pharmacologic, regulatory)Additional content defined by implementations
    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:type.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:type.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 Valuetype
      10. Extension.extension:type.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
      BindingFor example codes, see For codes, see MedicationClassificationTypeVS
      (example to http://hl7.org/fhir/ValueSet/medication-classification-type)
      TypeCodeableConcept, 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, ParameterDefinition, dateTime, code, string, 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
      Summaryfalse
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      12. Extension.extension:classification
      Slice Nameclassification
      Definition

      A specific classification concept drawn from the scheme declared in the type sub-extension. For example, if type is 'therapeutic', this carries a therapeutic-class code; if type is 'anatomical', an anatomical-group code (such as an ATC level-1 code). Multiple codes may be provided when a medication belongs to more than one class within the same scheme.

      ShortThe specific classification code within the scheme declared in type (e.g., an ATC code, a therapeutic-class code)Additional content defined by implementations
      Control0..*
      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:classification.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:classification.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 Valueclassification
        18. Extension.extension:classification.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
        TypeCodeableConcept, 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, ParameterDefinition, dateTime, code, string, 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
        Summaryfalse
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        20. Extension.extension:source
        Slice Namesource
        Definition

        The authority, publication, or system that supplied this classification (free text or URI). Useful when the classification is not directly resolvable from the type coding system, or to record a specific edition/jurisdictional publisher.

        ShortThe source or reference for the classification (as a string or URI)Additional 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:source.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:source.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 Valuesource
          26. Extension.extension:source.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
          TypeChoice of: string, uri, 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, 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/medication-classification
          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

          Provides a classification for a medication. This allows a Medication resource to carry classification information (e.g., therapeutic class, pharmacologic class) in , including the type of classification system used, one or more classification codes, and an optional source reference.

          ShortMedication Classification
          2. Extension.extension
          Control1..?
          4. Extension.extension:type
          Slice Nametype
          Definition

          Identifies the kind of classification being expressed — that is, the conceptual dimension along which the medication is being grouped. Examples include anatomical class, therapeutic class, pharmacologic class, mechanism of action, chemical-structure class, regulatory classification, controlled-substance schedule, legal or marketing status, reimbursement or formulary class, and public-health lists such as the WHO Essential Medicines List. Note that coding systems such as WHO ATC are not themselves a 'type'; an ATC code expresses an anatomical, therapeutic, pharmacologic, or chemical classification depending on the hierarchy level used. The specific code(s) from such a system are carried in the classification sub-extension.

          ShortThe kind of classification (e.g., anatomical, therapeutic, pharmacologic, regulatory)
          Control1..1
          6. Extension.extension:type.extension
          Control0..0
          8. Extension.extension:type.url
          Fixed Valuetype
          10. Extension.extension:type.value[x]
          BindingFor example codes, see MedicationClassificationTypeVS
          (example to http://hl7.org/fhir/ValueSet/medication-classification-type)
          TypeCodeableConcept
          [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
          12. Extension.extension:classification
          Slice Nameclassification
          Definition

          A specific classification concept drawn from the scheme declared in the type sub-extension. For example, if type is 'therapeutic', this carries a therapeutic-class code; if type is 'anatomical', an anatomical-group code (such as an ATC level-1 code). Multiple codes may be provided when a medication belongs to more than one class within the same scheme.

          ShortThe specific classification code within the scheme declared in type (e.g., an ATC code, a therapeutic-class code)
          Control0..*
          14. Extension.extension:classification.extension
          Control0..0
          16. Extension.extension:classification.url
          Fixed Valueclassification
          18. Extension.extension:classification.value[x]
          TypeCodeableConcept
          [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
          20. Extension.extension:source
          Slice Namesource
          Definition

          The authority, publication, or system that supplied this classification (free text or URI). Useful when the classification is not directly resolvable from the type coding system, or to record a specific edition/jurisdictional publisher.

          ShortThe source or reference for the classification (as a string or URI)
          Control0..1
          22. Extension.extension:source.extension
          Control0..0
          24. Extension.extension:source.url
          Fixed Valuesource
          26. Extension.extension:source.value[x]
          TypeChoice of: string, uri
          [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
          28. Extension.url
          Fixed Valuehttp://hl7.org/fhir/StructureDefinition/medication-classification
          30. Extension.value[x]
          Control0..0

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

          0. Extension
          Definition

          Provides a classification for a medication. This allows a Medication resource to carry classification information (e.g., therapeutic class, pharmacologic class) in , including the type of classification system used, one or more classification codes, and an optional source reference.

          ShortMedication Classification
          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

          An Extension

          ShortExtension
          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())
          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:type
            Slice Nametype
            Definition

            Identifies the kind of classification being expressed — that is, the conceptual dimension along which the medication is being grouped. Examples include anatomical class, therapeutic class, pharmacologic class, mechanism of action, chemical-structure class, regulatory classification, controlled-substance schedule, legal or marketing status, reimbursement or formulary class, and public-health lists such as the WHO Essential Medicines List. Note that coding systems such as WHO ATC are not themselves a 'type'; an ATC code expresses an anatomical, therapeutic, pharmacologic, or chemical classification depending on the hierarchy level used. The specific code(s) from such a system are carried in the classification sub-extension.

            ShortThe kind of classification (e.g., anatomical, therapeutic, pharmacologic, regulatory)
            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:type.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:type.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:type.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 Valuetype
              14. Extension.extension:type.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
              BindingFor example codes, see MedicationClassificationTypeVS
              (example to http://hl7.org/fhir/ValueSet/medication-classification-type)
              TypeCodeableConcept
              [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
              Is Modifierfalse
              Summaryfalse
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              16. Extension.extension:classification
              Slice Nameclassification
              Definition

              A specific classification concept drawn from the scheme declared in the type sub-extension. For example, if type is 'therapeutic', this carries a therapeutic-class code; if type is 'anatomical', an anatomical-group code (such as an ATC level-1 code). Multiple codes may be provided when a medication belongs to more than one class within the same scheme.

              ShortThe specific classification code within the scheme declared in type (e.g., an ATC code, a therapeutic-class code)
              Control0..*
              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:classification.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:classification.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:classification.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 Valueclassification
                24. Extension.extension:classification.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
                TypeCodeableConcept
                [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
                Is Modifierfalse
                Summaryfalse
                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                26. Extension.extension:source
                Slice Namesource
                Definition

                The authority, publication, or system that supplied this classification (free text or URI). Useful when the classification is not directly resolvable from the type coding system, or to record a specific edition/jurisdictional publisher.

                ShortThe source or reference for the classification (as a string or URI)
                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:source.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:source.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:source.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 Valuesource
                  34. Extension.extension:source.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
                  TypeChoice of: string, uri
                  [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/medication-classification
                  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()))