Extensions for Using Data Elements from FHIR R4B in FHIR STU3
0.1.0 - STU International flag

Extensions for Using Data Elements from FHIR R4B in FHIR STU3 - Downloaded Version null See the Directory of published versions

Extension: ExtensionPlanDefinition_Text - Detailed Descriptions

Page standards status: Trial-use Maturity Level: 0

Definitions for the ext-R4B-PlanDefinition.text extension.

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

0. Extension
Definition

R4B: PlanDefinition.text additional types (Narrative) additional types from child elements (div, status)


Optional Extension Element - found in all resources.

ShortR4B: text additional typesOptional Extensions Element
Comments

Element PlanDefinition.text is mapped to FHIR STU3 element PlanDefinition.text as SourceIsBroaderThanTarget. The mappings for PlanDefinition.text do not cover the following types: Narrative. The mappings for PlanDefinition.text do not cover the following types based on type expansion: div, status. Contained resources do not have narrative. Resources that are not contained SHOULD have a narrative. In some cases, a resource may only have text with little or no additional discrete data (as long as all minOccurs=1 elements are satisfied). This may be necessary for data from legacy systems where information is captured as a "text blob" or where text is additionally entered raw or narrated and encoded information is added later.

Control0..1*
This element is affected by the following invariants: ele-1
Is Modifierfalse
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() | (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
ele-1: All FHIR elements must have a @value or children (hasValue() | (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. In order to make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to 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..*
TypeExtension
Alternate Namesextensions, user content
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:_datatype
    Slice Name_datatype
    Definition

    Slice to indicate the presence of a R4B Narrative in FHIR STU3

    ShortDataType slice for a FHIR R4B `Narrative` valueAdditional Content defined by implementations
    Control10..1*
    TypeExtension
    6. Extension.extension:_datatype.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
    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.
    Fixed Valuehttp://hl7.org/fhir/StructureDefinition/_datatype
    8. Extension.extension:_datatype.value[x]
    Definition

    Value of extension - may be a resource or one of a constrained set of the data types (see Extensibility in the spec for list).

    ShortValue of extension
    Comments

    Must be: Narrative

    Control10..1
    Typestring, date, dateTime, Meta, code, Address, Attachment, integer, oid, Count, instant, ContactPoint, HumanName, Money, Identifier, Coding, markdown, SampledData, Ratio, id, positiveInt, Age, Distance, Reference, Period, Quantity, Duration, Range, uri, Annotation, boolean, base64Binary, Signature, unsignedInt, time, Timing, decimal, CodeableConcept
    [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
    Fixed ValueNarrative
    10. Extension.extension:status
    Slice Namestatus
    Definition

    R4B: Narrative.status

    ShortR4B: statusAdditional Content defined by implementations
    Comments

    Element Narrative.status is mapped to FHIR STU3 element Narrative.status as Equivalent.

    Control10..1*
    TypeExtension
    Requirements

    Element Narrative.status is mapped to FHIR STU3 element Narrative.status as Equivalent.

    12. Extension.extension:status.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
    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.
    Fixed Valuestatus
    14. Extension.extension:status.value[x]
    Definition

    The status of the narrative - whether it's entirely generated (from just the defined data or the extensions too), or whether a human authored it and it may contain additional data.


    Value of extension - may be a resource or one of a constrained set of the data types (see Extensibility in the spec for list).

    Shortgenerated | extensions | additional | emptyValue of extension
    Control10..1
    BindingThe codes SHALL be taken from For codes, see NarrativeStatus
    (required to http://hl7.org/fhir/ValueSet/narrative-status|3.0.2)
    Typecode, date, dateTime, Meta, string, Address, Attachment, integer, oid, Count, instant, ContactPoint, HumanName, Money, Identifier, Coding, markdown, SampledData, Ratio, id, positiveInt, Age, Distance, Reference, Period, Quantity, Duration, Range, uri, Annotation, boolean, base64Binary, Signature, unsignedInt, time, Timing, decimal, CodeableConcept
    [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
    16. Extension.extension:div
    Slice Namediv
    Definition

    R4B: Narrative.div

    ShortR4B: divAdditional Content defined by implementations
    Comments

    Element Narrative.div is mapped to FHIR STU3 element Narrative.div as Equivalent. The contents of the html element are an XHTML fragment containing only the basic html formatting elements described in chapters 7-11 and 15 of the HTML 4.0 standard, <a> elements (either name or href), images and internally contained stylesheets. The XHTML content SHALL NOT contain a head, a body, external stylesheet references, scripts, forms, base/link/xlink, frames, iframes and objects.

    Control10..1*
    TypeExtension
    Requirements

    Element Narrative.div is mapped to FHIR STU3 element Narrative.div as Equivalent.

    18. Extension.extension:div.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
    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.
    Fixed Valuediv
    20. Extension.extension:div.value[x]
    Definition

    The actual narrative content, a stripped down version of XHTML.


    Value of extension - may be a resource or one of a constrained set of the data types (see Extensibility in the spec for list).

    ShortLimited xhtml contentValue of extension
    Comments

    The contents of the html element are an XHTML fragment containing only the basic html formatting elements described in chapters 7-11 and 15 of the HTML 4.0 standard, <a> elements (either name or href), images and internally contained stylesheets. The XHTML content SHALL NOT contain a head, a body, external stylesheet references, scripts, forms, base/link/xlink, frames, iframes and objects.

    Control10..1
    Typeuri, date, dateTime, Meta, code, string, Address, Attachment, integer, oid, Count, instant, ContactPoint, HumanName, Money, Identifier, Coding, markdown, SampledData, Ratio, id, positiveInt, Age, Distance, Reference, Period, Quantity, Duration, Range, Annotation, boolean, base64Binary, Signature, unsignedInt, time, Timing, decimal, CodeableConcept
    [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
    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
    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.
    Fixed Valuehttp://hl7.org/fhir/4.3/StructureDefinition/extension-PlanDefinition.text
    24. Extension.value[x]
    Definition

    Value of extension - may be a resource or one of a constrained set of the data types (see Extensibility in the spec for list).

    ShortValue of extension
    Control0..01
    TypeChoice of: base64Binary, boolean, code, date, dateTime, decimal, id, instant, integer, markdown, oid, positiveInt, string, time, unsignedInt, uri, Address, Age, Annotation, Attachment, CodeableConcept, Coding, ContactPoint, Count, Distance, Duration, HumanName, Identifier, Money, Period, Quantity, Range, Ratio, Reference, SampledData, Signature, Timing, Meta
    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension

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

    0. Extension
    Definition

    R4B: PlanDefinition.text additional types (Narrative) additional types from child elements (div, status)

    ShortR4B: text additional types
    Comments

    Element PlanDefinition.text is mapped to FHIR STU3 element PlanDefinition.text as SourceIsBroaderThanTarget. The mappings for PlanDefinition.text do not cover the following types: Narrative. The mappings for PlanDefinition.text do not cover the following types based on type expansion: div, status. Contained resources do not have narrative. Resources that are not contained SHOULD have a narrative. In some cases, a resource may only have text with little or no additional discrete data (as long as all minOccurs=1 elements are satisfied). This may be necessary for data from legacy systems where information is captured as a "text blob" or where text is additionally entered raw or narrated and encoded information is added later.

    Control0..1
    Is Modifierfalse
    2. Extension.extension
    Control0..*
    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:_datatype
      Slice Name_datatype
      Definition

      Slice to indicate the presence of a R4B Narrative in FHIR STU3

      ShortDataType slice for a FHIR R4B `Narrative` value
      Control1..1
      6. Extension.extension:_datatype.url
      Control1..1
      Fixed Valuehttp://hl7.org/fhir/StructureDefinition/_datatype
      8. Extension.extension:_datatype.value[x]
      Comments

      Must be: Narrative

      Control1..1
      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
      Fixed ValueNarrative
      10. Extension.extension:status
      Slice Namestatus
      Definition

      R4B: Narrative.status

      ShortR4B: status
      Comments

      Element Narrative.status is mapped to FHIR STU3 element Narrative.status as Equivalent.

      Control1..1
      Requirements

      Element Narrative.status is mapped to FHIR STU3 element Narrative.status as Equivalent.

      12. Extension.extension:status.url
      Control1..1
      Fixed Valuestatus
      14. Extension.extension:status.value[x]
      Definition

      The status of the narrative - whether it's entirely generated (from just the defined data or the extensions too), or whether a human authored it and it may contain additional data.

      Shortgenerated | extensions | additional | empty
      Control1..1
      BindingThe codes SHALL be taken from NarrativeStatus
      (required to http://hl7.org/fhir/ValueSet/narrative-status|3.0.2)
      Typecode
      [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
      16. Extension.extension:div
      Slice Namediv
      Definition

      R4B: Narrative.div

      ShortR4B: div
      Comments

      Element Narrative.div is mapped to FHIR STU3 element Narrative.div as Equivalent. The contents of the html element are an XHTML fragment containing only the basic html formatting elements described in chapters 7-11 and 15 of the HTML 4.0 standard, <a> elements (either name or href), images and internally contained stylesheets. The XHTML content SHALL NOT contain a head, a body, external stylesheet references, scripts, forms, base/link/xlink, frames, iframes and objects.

      Control1..1
      Requirements

      Element Narrative.div is mapped to FHIR STU3 element Narrative.div as Equivalent.

      18. Extension.extension:div.url
      Control1..1
      Fixed Valuediv
      20. Extension.extension:div.value[x]
      Definition

      The actual narrative content, a stripped down version of XHTML.

      ShortLimited xhtml content
      Comments

      The contents of the html element are an XHTML fragment containing only the basic html formatting elements described in chapters 7-11 and 15 of the HTML 4.0 standard, <a> elements (either name or href), images and internally contained stylesheets. The XHTML content SHALL NOT contain a head, a body, external stylesheet references, scripts, forms, base/link/xlink, frames, iframes and objects.

      Control1..1
      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
      22. Extension.url
      Control1..1
      Fixed Valuehttp://hl7.org/fhir/4.3/StructureDefinition/extension-PlanDefinition.text
      24. Extension.value[x]
      Control0..0

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

      0. Extension
      Definition

      R4B: PlanDefinition.text additional types (Narrative) additional types from child elements (div, status)

      ShortR4B: text additional types
      Comments

      Element PlanDefinition.text is mapped to FHIR STU3 element PlanDefinition.text as SourceIsBroaderThanTarget. The mappings for PlanDefinition.text do not cover the following types: Narrative. The mappings for PlanDefinition.text do not cover the following types based on type expansion: div, status. Contained resources do not have narrative. Resources that are not contained SHOULD have a narrative. In some cases, a resource may only have text with little or no additional discrete data (as long as all minOccurs=1 elements are satisfied). This may be necessary for data from legacy systems where information is captured as a "text blob" or where text is additionally entered raw or narrated and encoded information is added later.

      Control0..1
      This element is affected by the following invariants: ele-1
      Is Modifierfalse
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() | (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.

      Shortxml:id (or equivalent in JSON)
      Control0..1
      Typestring
      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.
      4. Extension.extension
      Definition

      An Extension

      ShortExtension
      Control0..*
      TypeExtension
      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:_datatype
        Slice Name_datatype
        Definition

        Slice to indicate the presence of a R4B Narrative in FHIR STU3

        ShortDataType slice for a FHIR R4B `Narrative` value
        Control1..1
        TypeExtension
        8. Extension.extension:_datatype.id
        Definition

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

        Shortxml:id (or equivalent in JSON)
        Control0..1
        Typestring
        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.
        10. Extension.extension:_datatype.extension
        Definition

        May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to 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
        Alternate Namesextensions, user content
        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:_datatype.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
          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.
          Fixed Valuehttp://hl7.org/fhir/StructureDefinition/_datatype
          14. Extension.extension:_datatype.value[x]
          Definition

          Value of extension - may be a resource or one of a constrained set of the data types (see Extensibility in the spec for list).

          ShortValue of extension
          Comments

          Must be: Narrative

          Control1..1
          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
          Fixed ValueNarrative
          16. Extension.extension:status
          Slice Namestatus
          Definition

          R4B: Narrative.status

          ShortR4B: status
          Comments

          Element Narrative.status is mapped to FHIR STU3 element Narrative.status as Equivalent.

          Control1..1
          TypeExtension
          Requirements

          Element Narrative.status is mapped to FHIR STU3 element Narrative.status as Equivalent.

          18. Extension.extension:status.id
          Definition

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

          Shortxml:id (or equivalent in JSON)
          Control0..1
          Typestring
          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.
          20. Extension.extension:status.extension
          Definition

          May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to 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
          Alternate Namesextensions, user content
          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:status.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
            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.
            Fixed Valuestatus
            24. Extension.extension:status.value[x]
            Definition

            The status of the narrative - whether it's entirely generated (from just the defined data or the extensions too), or whether a human authored it and it may contain additional data.

            Shortgenerated | extensions | additional | empty
            Control1..1
            BindingThe codes SHALL be taken from NarrativeStatus
            (required to http://hl7.org/fhir/ValueSet/narrative-status|3.0.2)
            Typecode
            [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.extension:div
            Slice Namediv
            Definition

            R4B: Narrative.div

            ShortR4B: div
            Comments

            Element Narrative.div is mapped to FHIR STU3 element Narrative.div as Equivalent. The contents of the html element are an XHTML fragment containing only the basic html formatting elements described in chapters 7-11 and 15 of the HTML 4.0 standard, <a> elements (either name or href), images and internally contained stylesheets. The XHTML content SHALL NOT contain a head, a body, external stylesheet references, scripts, forms, base/link/xlink, frames, iframes and objects.

            Control1..1
            TypeExtension
            Requirements

            Element Narrative.div is mapped to FHIR STU3 element Narrative.div as Equivalent.

            28. Extension.extension:div.id
            Definition

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

            Shortxml:id (or equivalent in JSON)
            Control0..1
            Typestring
            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.
            30. Extension.extension:div.extension
            Definition

            May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to 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
            Alternate Namesextensions, user content
            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:div.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
              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.
              Fixed Valuediv
              34. Extension.extension:div.value[x]
              Definition

              The actual narrative content, a stripped down version of XHTML.

              ShortLimited xhtml content
              Comments

              The contents of the html element are an XHTML fragment containing only the basic html formatting elements described in chapters 7-11 and 15 of the HTML 4.0 standard, <a> elements (either name or href), images and internally contained stylesheets. The XHTML content SHALL NOT contain a head, a body, external stylesheet references, scripts, forms, base/link/xlink, frames, iframes and objects.

              Control1..1
              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
              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
              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.
              Fixed Valuehttp://hl7.org/fhir/4.3/StructureDefinition/extension-PlanDefinition.text
              38. Extension.value[x]
              Definition

              Value of extension - may be a resource or one of a constrained set of the data types (see Extensibility in the spec for list).

              ShortValue of extension
              Control0..0
              TypeChoice of: base64Binary, boolean, code, date, dateTime, decimal, id, instant, integer, markdown, oid, positiveInt, string, time, unsignedInt, uri, Address, Age, Annotation, Attachment, CodeableConcept, Coding, ContactPoint, Count, Distance, Duration, HumanName, Identifier, Money, Period, Quantity, Range, Ratio, Reference, SampledData, Signature, Timing, Meta
              Primitive ValueThis primitive element may be present, or absent, or replaced by an extension