DK MedCom Messaging
3.0.0 - release Denmark flag

This page is part of the DK MedCom Messaging (v3.0.0: Release) based on FHIR (HL7® FHIR® Standard) R4. This is the current published version. For a full list of available versions, see the Directory of published versions

Resource Profile: MedComMessagingMessageHeader - Detailed Descriptions

Active as of 2025-05-14

Definitions for the medcom-messaging-messageHeader resource profile.

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

0. MessageHeader
Definition

The header for a message exchange that is either requesting or responding to an action. The reference(s) that are the subject of the action as well as other information related to the action are typically transmitted in a bundle in which the MessageHeader resource instance is the first resource in the bundle.

ShortA resource that describes a message that is exchanged between systems
Control0..*
Is Modifierfalse
Summaryfalse
Invariantsdom-2: If the resource is contained in another resource, it SHALL NOT contain nested Resources (contained.contained.empty())
dom-3: If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource or SHALL refer to the containing resource (contained.where((('#'+id in (%resource.descendants().reference | %resource.descendants().as(canonical) | %resource.descendants().as(uri) | %resource.descendants().as(url))) or descendants().where(reference = '#').exists() or descendants().where(as(canonical) = '#').exists() or descendants().where(as(canonical) = '#').exists()).not()).trace('unmatched', id).empty())
dom-4: If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated (contained.meta.versionId.empty() and contained.meta.lastUpdated.empty())
dom-5: If a resource is contained in another resource, it SHALL NOT have a security label (contained.meta.security.empty())
dom-6: A resource should have narrative for robust management (text.`div`.exists())
2. MessageHeader.id
Definition

The logical id of the resource, as used in the URL for the resource. Once assigned, this value never changes.

ShortEach message shall include a globally unique id.Logical id of this artifact
Comments

The only time that a resource does not have an id is when it is being submitted to the server using a create operation.

Control10..1
Typeidstring
Is Modifierfalse
Must Supporttrue
Summarytrue
4. MessageHeader.implicitRules
Definition

A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc.

ShortA set of rules under which this content was created
Comments

Asserting this rule set restricts the content to be only understood by a limited set of trading partners. This inherently limits the usefulness of the data in the long term. However, the existing health eco-system is highly fractured, and not yet ready to define, collect, and exchange data in a generally computable sense. Wherever possible, implementers and/or specification writers should avoid using this element. Often, when used, the URL is a reference to an implementation guide that defines these special rules as part of it's narrative along with other profiles, value sets, etc.

Control0..1
Typeuri
Is Modifiertrue because This element is labeled as a modifier because the implicit rules may provide additional knowledge about the resource that modifies it's meaning or interpretation
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summarytrue
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
6. MessageHeader.text
Definition

A human-readable narrative that contains a summary of the resource and can be used to represent the content of the resource to a human. The narrative need not encode all the structured data, but is required to contain sufficient detail to make it "clinically safe" for a human to just read the narrative. Resource definitions may define what content should be represented in the narrative to ensure clinical safety.

ShortA summary of the resource content. The narrative text shall always be included when exchanging a MedCom message. All MustSupport elements and extensions shall be included.Text summary of the resource, for human interpretation
Comments

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
TypeNarrative
Is Modifierfalse
Must Supporttrue
Summaryfalse
Alternate Namesnarrative, html, xhtml, display
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
8. MessageHeader.modifierExtension
Definition

May be used to represent additional information that is not part of the basic definition of the resource and that modifies the understanding of the element that contains it and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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. Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

ShortExtensions that cannot be ignored
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 Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the resource that contains them
Summaryfalse
Requirements

Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

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())
10. MessageHeader.event[x]
Definition

Code that identifies the event this message represents and connects it with its definition. Events defined as part of the FHIR specification have the system value "http://terminology.hl7.org/CodeSystem/message-events". Alternatively uri to the EventDefinition.

ShortThe event element shall contain a value from MedComMessagingMessageTypesCode for the event this message represents or link to event definition
Comments

The time of the event will be found in the focus resource. The time of the message will be found in Bundle.timestamp.


The time of the event will be found in the focus resource. The time of the message will be found in Bundle.timestamp.

Control1..1
BindingThe codes SHALL be taken from For example codes, see MedComMessagingMessageTypeshttp://hl7.org/fhir/ValueSet/message-events
(required to http://medcomfhir.dk/ig/terminology/ValueSet/medcom-messaging-messageTypes)
TypeCoding, uri
[x] NoteSeeChoice of Data Typesfor further information about how to use [x]
Is Modifierfalse
Must Supporttrue
Summarytrue
Requirements

Drives the behavior associated with this message.

Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
12. MessageHeader.event[x].code
Definition

A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).

ShortSymbol in syntax defined by the system
Control10..1
Typecode
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summarytrue
Requirements

Need to refer to a particular code in the system.

Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
14. MessageHeader.destination
Definition

The destination application which the message is intended for.

ShortMessage destination application(s)
Comments

There SHOULD be at least one destination, but in some circumstances, the source system is unaware of any particular destination system.

Control10..*
TypeBackboneElement
Is Modifierfalse
Summarytrue
Requirements

Indicates where message is to be sent for routing purposes. Allows verification of "am I the intended recipient".

Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
SlicingThis element introduces a set of slices on MessageHeader.destination. The slices areUnordered and Closed, and can be differentiated using the following discriminators:
  • value @ $this.extension.value
  • 16. MessageHeader.destination.modifierExtension
    Definition

    May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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 can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

    Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

    ShortExtensions that cannot be ignored even if unrecognized
    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 Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
    Summarytrue
    Requirements

    Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

    Alternate Namesextensions, user content, modifiers
    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. MessageHeader.destination.endpoint
    Definition

    Indicates where the message should be routed to.

    ShortActual destination address or id
    Comments

    The id may be a non-resolvable URI for systems that do not use standard network-based addresses.

    Control1..1
    Typeurl
    Is Modifierfalse
    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
    Summarytrue
    Requirements

    Identifies where to route the message.

    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    20. MessageHeader.destination:primary
    Slice Nameprimary
    Definition

    The destination application which the message is intended for.

    ShortMessage destination application(s)
    Comments

    There SHOULD be at least one destination, but in some circumstances, the source system is unaware of any particular destination system.

    Control10..1*
    TypeBackboneElement
    Is Modifierfalse
    Summarytrue
    Requirements

    Indicates where message is to be sent for routing purposes. Allows verification of "am I the intended recipient".

    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    22. MessageHeader.destination:primary.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 manageable, 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 MessageHeader.destination.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
    • value @ url
    • 24. MessageHeader.destination:primary.extension:use
      Slice Nameuse
      Definition

      Indicates whether the use of a destination in a MedCom message header is as a primary or a carbon copy recipient of the message

      ShortMedComDestinationUseExtension
      Control1..1
      This element is affected by the following invariants: ele-1
      TypeExtension(MedComDestinationUseExtension) (Extension Type: Coding)
      Is Modifierfalse
      Must Supporttrue
      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())
      ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
      26. MessageHeader.destination:primary.extension:use.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 manageable, 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 MessageHeader.destination.extension.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
      • value @ url
      • 28. MessageHeader.destination:primary.extension:use.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://medcomfhir.dk/ig/messaging/StructureDefinition/medcom-messaging-destinationUseExtension
        30. MessageHeader.destination:primary.extension:use.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
        Control10..1
        TypeCoding, date, Meta, Address, Attachment, integer, Count, DataRequirement, Dosage, uuid, Identifier, SampledData, id, positiveInt, Distance, Period, Duration, canonical, Range, RelatedArtifact, base64Binary, UsageContext, Timing, decimal, CodeableConcept, ParameterDefinition, dateTime, code, string, Contributor, oid, instant, ContactPoint, HumanName, Money, markdown, Ratio, Age, Reference, TriggerDefinition, Quantity, uri, url, Annotation, ContactDetail, boolean, Expression, Signature, unsignedInt, time
        [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
        Is Modifierfalse
        Summaryfalse
        Pattern Value{
          "system" : "http://medcomfhir.dk/ig/terminology/CodeSystem/medcom-messaging-destinationUse",
          "code" : "primary"
        }
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        32. MessageHeader.destination:primary.extension:use.value[x].system
        Definition

        The identification of the code system that defines the meaning of the symbol in the code.

        ShortIdentity of the terminology system
        Comments

        The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should reference to some definition that establishes the system clearly and unambiguously.

        Control0..1
        Typeuri
        Is Modifierfalse
        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
        Summarytrue
        Requirements

        Need to be unambiguous about the source of the definition of the symbol.

        Pattern Valuehttp://medcomfhir.dk/ig/terminology/CodeSystem/medcom-messaging-destinationUse
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        34. MessageHeader.destination:primary.modifierExtension
        Definition

        May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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 can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

        Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

        ShortExtensions that cannot be ignored even if unrecognized
        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 Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
        Summarytrue
        Requirements

        Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

        Alternate Namesextensions, user content, modifiers
        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())
        36. MessageHeader.destination:primary.endpoint
        Definition

        Indicates where the message should be routed to.

        ShortActual destination address or id
        Comments

        The id may be a non-resolvable URI for systems that do not use standard network-based addresses.

        Control1..1
        Typeurl
        Is Modifierfalse
        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
        Must Supporttrue
        Summarytrue
        Requirements

        Identifies where to route the message.

        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        38. MessageHeader.destination:primary.receiver
        Definition

        Allows data conveyed by a message to be addressed to a particular person or department when routing to a specific application isn't sufficient.

        ShortThe primary reciever of the messageIntended "real-world" recipient for the data
        Control10..1
        TypeReference(MedComMessagingOrganization, Practitioner, PractitionerRole, Organization)bundled
        Is Modifierfalse
        Must Supporttrue
        Summarytrue
        Requirements

        Allows routing beyond just the application level.

        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        40. MessageHeader.destination:cc
        Slice Namecc
        Definition

        The destination application which the message is intended for.

        ShortMessage destination application(s)
        Comments

        There SHOULD be at least one destination, but in some circumstances, the source system is unaware of any particular destination system.

        Control0..*
        TypeBackboneElement
        Is Modifierfalse
        Summarytrue
        Requirements

        Indicates where message is to be sent for routing purposes. Allows verification of "am I the intended recipient".

        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        42. MessageHeader.destination:cc.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 manageable, 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 MessageHeader.destination.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
        • value @ url
        • 44. MessageHeader.destination:cc.extension:use
          Slice Nameuse
          Definition

          Indicates whether the use of a destination in a MedCom message header is as a primary or a carbon copy recipient of the message

          ShortMedComDestinationUseExtension
          Control1..1
          This element is affected by the following invariants: ele-1
          TypeExtension(MedComDestinationUseExtension) (Extension Type: Coding)
          Is Modifierfalse
          Must Supporttrue
          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())
          ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
          46. MessageHeader.destination:cc.extension:use.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 manageable, 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 MessageHeader.destination.extension.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
          • value @ url
          • 48. MessageHeader.destination:cc.extension:use.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://medcomfhir.dk/ig/messaging/StructureDefinition/medcom-messaging-destinationUseExtension
            50. MessageHeader.destination:cc.extension:use.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
            Control10..1
            TypeCoding, date, Meta, Address, Attachment, integer, Count, DataRequirement, Dosage, uuid, Identifier, SampledData, id, positiveInt, Distance, Period, Duration, canonical, Range, RelatedArtifact, base64Binary, UsageContext, Timing, decimal, CodeableConcept, ParameterDefinition, dateTime, code, string, Contributor, oid, instant, ContactPoint, HumanName, Money, markdown, Ratio, Age, Reference, TriggerDefinition, Quantity, uri, url, Annotation, ContactDetail, boolean, Expression, Signature, unsignedInt, time
            [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
            Is Modifierfalse
            Summaryfalse
            Pattern Value{
              "system" : "http://medcomfhir.dk/ig/terminology/CodeSystem/medcom-messaging-destinationUse",
              "code" : "cc"
            }
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            52. MessageHeader.destination:cc.extension:use.value[x].system
            Definition

            The identification of the code system that defines the meaning of the symbol in the code.

            ShortIdentity of the terminology system
            Comments

            The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should reference to some definition that establishes the system clearly and unambiguously.

            Control0..1
            Typeuri
            Is Modifierfalse
            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
            Summarytrue
            Requirements

            Need to be unambiguous about the source of the definition of the symbol.

            Pattern Valuehttp://medcomfhir.dk/ig/terminology/CodeSystem/medcom-messaging-destinationUse
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            54. MessageHeader.destination:cc.modifierExtension
            Definition

            May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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 can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

            Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

            ShortExtensions that cannot be ignored even if unrecognized
            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 Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
            Summarytrue
            Requirements

            Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

            Alternate Namesextensions, user content, modifiers
            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())
            56. MessageHeader.destination:cc.endpoint
            Definition

            Indicates where the message should be routed to.

            ShortActual destination address or id
            Comments

            The id may be a non-resolvable URI for systems that do not use standard network-based addresses.

            Control1..1
            Typeurl
            Is Modifierfalse
            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
            Must Supporttrue
            Summarytrue
            Requirements

            Identifies where to route the message.

            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            58. MessageHeader.destination:cc.receiver
            Definition

            Allows data conveyed by a message to be addressed to a particular person or department when routing to a specific application isn't sufficient.

            ShortThe carbon copy reciever of the message. Is only used when a message has multiple recievers.Intended "real-world" recipient for the data
            Control10..1
            TypeReference(MedComMessagingOrganization, Practitioner, PractitionerRole, Organization)bundled
            Is Modifierfalse
            Must Supporttrue
            Summarytrue
            Requirements

            Allows routing beyond just the application level.

            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            60. MessageHeader.sender
            Definition

            Identifies the sending system to allow the use of a trust relationship.

            ShortThe actual sender of the messageReal world sender of the message
            Comments

            Use case is for where a (trusted) sending system is responsible for multiple organizations, and therefore cannot differentiate based on source endpoint / authentication alone.

            Control10..1
            TypeReference(MedComMessagingOrganization, Practitioner, PractitionerRole, Organization)bundled
            Is Modifierfalse
            Must Supporttrue
            Summarytrue
            Requirements

            Allows routing beyond just the application level.

            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            62. MessageHeader.source
            Definition

            The source application from which this message originated.

            ShortContains the information about the target for the Acknowledgement message.Message source application
            Control1..1
            TypeBackboneElement
            Is Modifierfalse
            Must Supporttrue
            Summarytrue
            Requirements

            Allows replies, supports audit.

            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            64. MessageHeader.source.modifierExtension
            Definition

            May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. 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 can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

            Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

            ShortExtensions that cannot be ignored even if unrecognized
            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 Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
            Summarytrue
            Requirements

            Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

            Alternate Namesextensions, user content, modifiers
            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())
            66. MessageHeader.source.endpoint
            Definition

            Identifies the routing target to send acknowledgements to.

            ShortActual message source address or id
            Comments

            The id may be a non-resolvable URI for systems that do not use standard network-based addresses.

            Control1..1
            Typeurl
            Is Modifierfalse
            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
            Must Supporttrue
            Summarytrue
            Requirements

            Identifies where to send responses, may influence security permissions.

            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            68. MessageHeader.definition
            Definition

            Permanent link to the MessageDefinition for this message.

            ShortLink to the definition for this message
            Control0..1
            Typecanonical(MessageDefinition)
            Is Modifierfalse
            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
            Must Supporttrue
            Summarytrue
            Requirements

            Allows sender to define the expected contents of the message.

            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))