HL7® Austria TC FHIR® Messaging
0.1.0 - ci-build

HL7® Austria TC FHIR® Messaging - Local Development build (v0.1.0) built by the FHIR (HL7® FHIR® Standard) Build Tools. See the Directory of published versions

Resource Profile: ATMessagingMessageHeader - Detailed Descriptions

Draft as of 2026-03-18

Definitions for the at-messaging-message-header resource profile.

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

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
Must Supportfalse
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().ofType(canonical) | %resource.descendants().ofType(uri) | %resource.descendants().ofType(url))) or descendants().where(reference = '#').exists() or descendants().where(ofType(canonical) = '#').exists() or descendants().where(ofType(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.

ShortLogical id of this artifact
Comments

Within the context of the FHIR RESTful interactions, the resource has an id except for cases like the create and conditional update. Otherwise, the use of the resouce id depends on the given use case.

Control10..1
Typeid
Is Modifierfalse
Must Supportfalse
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 its 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 its meaning or interpretation
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supportfalse
Summarytrue
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
6. MessageHeader.contained
Definition

These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, nor can they have their own independent transaction scope. This is allowed to be a Parameters resource if and only if it is referenced by a resource that provides context/meaning.

ShortContained, inline Resources
Comments

This should never be done when the content can be identified properly, as once identification is lost, it is extremely difficult (and context dependent) to restore it again. Contained resources may have profiles and tags in their meta elements, but SHALL NOT have security labels.

Control0..*
This element is affected by the following invariants: dom-2, dom-4, dom-3, dom-5
TypeResource
Is Modifierfalse
Must Supportfalse
Summaryfalse
Alternate Namesinline resources, anonymous resources, contained resources
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 managable, 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
Must Supportfalse
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
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 are defined by the implementation. Alternatively a canonical uri to the EventDefinition.

ShortEvent code or link to EventDefinition
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
BindingUnless not suitable, these codes SHALL be taken from For example codes, see AT Message Event Type ValueSet
(extensible to http://fhir.hl7.at/fhir/ATMessaging/0.1.0/ValueSet/at-messaging-event-type-vs)
TypeCoding, canonical(EventDefinition)
[x] NoteSeeChoice of Data Typesfor further information about how to use [x]
Is Modifierfalse
Must Supportfalse
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].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 be an absolute reference to some definition that establishes the system clearly and unambiguously.

Control10..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.

Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
14. 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
This element is affected by the following invariants: cod-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()))
16. 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..1*
TypeBackboneElement
Is Modifierfalse
Must Supportfalse
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()))
18. 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 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. 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())
20. MessageHeader.destination.endpoint[x]
Definition

Indicates where the message should be routed.

ShortActual destination address or Endpoint resource
Comments

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

Control10..1
TypeReference(AT Messaging Endpoint, Endpoint), url
[x] NoteSeeChoice of Data Typesfor further information about how to use [x]
Is Modifierfalse
Must Supportfalse
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()))
22. MessageHeader.destination.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.

ShortIntended "real-world" recipient for the data
Control10..1
TypeReference(HL7® AT Core Practitioner Profile, HL7® AT Core PractitionerRole Profile, HL7® AT Core Organization Profile, Practitioner, PractitionerRole, Organization)
Is Modifierfalse
Must Supportfalse
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()))
24. MessageHeader.sender
Definition

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

ShortReal 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. Proposing to remove and rely on Task to convey this information.

Control0..1
TypeReference(HL7® AT Core Practitioner Profile, HL7® AT Core PractitionerRole Profile, HL7® AT Core Organization Profile, Practitioner, PractitionerRole, Device, Organization)
Is Modifierfalse
Must Supportfalse
Obligations
    ObligationsActor
    SHOULD:populateSender Actor
    SHALL:handleReceiver Actor
    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()))
    26. MessageHeader.author
    Definition

    The logical author of the message - the personor device that decided the described event should happen. When there is more than one candidate, pick the most proximal to the MessageHeader. Can provide other authors in extensions.

    ShortThe source of the decision
    Comments

    Usually only for the request but can be used in a response.Proposing to remove and rely on Task to convey this information.

    Control0..1
    TypeReference(HL7® AT Core Practitioner Profile, HL7® AT Core PractitionerRole Profile, HL7® AT Core Organization Profile, Practitioner, PractitionerRole, Device, Organization)
    Is Modifierfalse
    Must Supportfalse
    Obligations
      ObligationsActor
      SHOULD:populateSender Actor
      SHALL:handleReceiver Actor
      Summarytrue
      Requirements

      Need to know for audit/traceback requirements and possibly for authorization.

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

      The source application from which this message originated.

      ShortMessage source application
      Control1..1
      TypeBackboneElement
      Is Modifierfalse
      Must Supportfalse
      Summarytrue
      Requirements

      Allows replies, supports audit.

      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      30. 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 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. 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())
      32. MessageHeader.source.endpoint[x]
      Definition

      Identifies the routing target to send acknowledgements to.

      ShortActual source address or Endpoint resource
      Comments

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

      Control10..1
      TypeReference(AT Messaging Endpoint, Endpoint), url
      [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
      Is Modifierfalse
      Must Supportfalse
      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()))
      34. MessageHeader.source.name
      Definition

      Human-readable name for the source system.

      ShortName of system
      Control10..1
      Typestring
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Must Supportfalse
      Summarytrue
      Requirements

      May be used to support audit.

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

      May include configuration or other information useful in debugging.

      ShortName of software running the system
      Control0..1
      Typestring
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Must Supportfalse
      Obligations
        ObligationsActor
        SHOULD:populateSender Actor
        Summarytrue
        Requirements

        Supports audit and possibly interface engine behavior.

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

        Can convey versions of multiple systems in situations where a message passes through multiple hands.

        ShortVersion of software running
        NoteThis is a business version Id, not a resource version Id (see discussion)
        Control10..1
        Typestring
        Is Modifierfalse
        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
        Must Supportfalse
        Summarytrue
        Requirements

        Supports audit and possibly interface engine behavior.

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

        An e-mail, phone, website or other contact point to use to resolve issues with message communications.

        ShortHuman contact for problems
        Control0..1
        TypeContactPoint
        Is Modifierfalse
        Must Supportfalse
        Obligations
          ObligationsActor
          SHOULD:populateSender Actor
          Summarytrue
          Requirements

          Allows escalation of technical issues.

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

          Permanent link to the MessageDefinition for this message.

          ShortLink to the definition for this message
          Control10..1
          Typecanonical(MessageDefinition)
          Is Modifierfalse
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Must Supportfalse
          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()))

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

          0. MessageHeader
          2. MessageHeader.id
          Control1..?
          4. MessageHeader.event[x]
          BindingUnless not suitable, these codes SHALL be taken from AT Message Event Type ValueSet
          (extensible to http://fhir.hl7.at/fhir/ATMessaging/0.1.0/ValueSet/at-messaging-event-type-vs)
          TypeCoding, canonical(EventDefinition)
          [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
          6. MessageHeader.event[x].system
          Control1..?
          8. MessageHeader.event[x].code
          Control1..?
          10. MessageHeader.destination
          Control1..1
          12. MessageHeader.destination.endpoint[x]
          Control1..?
          TypeReference(AT Messaging Endpoint), url
          [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
          14. MessageHeader.destination.receiver
          Control1..?
          TypeReference(HL7® AT Core Practitioner Profile, HL7® AT Core PractitionerRole Profile, HL7® AT Core Organization Profile)
          16. MessageHeader.sender
          TypeReference(HL7® AT Core Practitioner Profile, HL7® AT Core PractitionerRole Profile, HL7® AT Core Organization Profile)
          Obligations
            ObligationsActor
            SHOULD:populateSender Actor
            SHALL:handleReceiver Actor
            18. MessageHeader.author
            TypeReference(HL7® AT Core Practitioner Profile, HL7® AT Core PractitionerRole Profile, HL7® AT Core Organization Profile)
            Obligations
              ObligationsActor
              SHOULD:populateSender Actor
              SHALL:handleReceiver Actor
              20. MessageHeader.source
              22. MessageHeader.source.endpoint[x]
              Control1..?
              TypeReference(AT Messaging Endpoint), url
              [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
              24. MessageHeader.source.name
              Control1..?
              26. MessageHeader.source.software
              Obligations
                ObligationsActor
                SHOULD:populateSender Actor
                28. MessageHeader.source.version
                NoteThis is a business version Id, not a resource version Id (see discussion)
                Control1..?
                30. MessageHeader.source.contact
                Obligations
                  ObligationsActor
                  SHOULD:populateSender Actor
                  32. MessageHeader.definition
                  Control1..?

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

                  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
                  Must Supportfalse
                  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().ofType(canonical) | %resource.descendants().ofType(uri) | %resource.descendants().ofType(url))) or descendants().where(reference = '#').exists() or descendants().where(ofType(canonical) = '#').exists() or descendants().where(ofType(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.

                  ShortLogical id of this artifact
                  Comments

                  Within the context of the FHIR RESTful interactions, the resource has an id except for cases like the create and conditional update. Otherwise, the use of the resouce id depends on the given use case.

                  Control1..1
                  Typeid
                  Is Modifierfalse
                  Must Supportfalse
                  Summarytrue
                  4. MessageHeader.meta
                  Definition

                  The metadata about the resource. This is content that is maintained by the infrastructure. Changes to the content might not always be associated with version changes to the resource.

                  ShortMetadata about the resource
                  Control0..1
                  TypeMeta
                  Is Modifierfalse
                  Must Supportfalse
                  Summarytrue
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  6. 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 its 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 its meaning or interpretation
                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                  Must Supportfalse
                  Summarytrue
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  8. MessageHeader.language
                  Definition

                  The base language in which the resource is written.

                  ShortLanguage of the resource content
                  Comments

                  Language is provided to support indexing and accessibility (typically, services such as text to speech use the language tag). The html language tag in the narrative applies to the narrative. The language tag on the resource may be used to specify the language of other presentations generated from the data in the resource. Not all the content has to be in the base language. The Resource.language should not be assumed to apply to the narrative automatically. If a language is specified, it should it also be specified on the div element in the html (see rules in HTML5 for information about the relationship between xml:lang and the html lang attribute).

                  Control0..1
                  BindingThe codes SHALL be taken from AllLanguages
                  (required to http://hl7.org/fhir/ValueSet/all-languages|5.0.0)

                  IETF language tag for a human language

                  Typecode
                  Is Modifierfalse
                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                  Must Supportfalse
                  Summaryfalse
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  10. 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.

                  ShortText summary of the resource, for human interpretation
                  Comments

                  Contained resources do not have a 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: dom-6
                  TypeNarrative
                  Is Modifierfalse
                  Must Supportfalse
                  Summaryfalse
                  Alternate Namesnarrative, html, xhtml, display
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  12. MessageHeader.contained
                  Definition

                  These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, nor can they have their own independent transaction scope. This is allowed to be a Parameters resource if and only if it is referenced by a resource that provides context/meaning.

                  ShortContained, inline Resources
                  Comments

                  This should never be done when the content can be identified properly, as once identification is lost, it is extremely difficult (and context dependent) to restore it again. Contained resources may have profiles and tags in their meta elements, but SHALL NOT have security labels.

                  Control0..*
                  This element is affected by the following invariants: dom-2, dom-4, dom-3, dom-5
                  TypeResource
                  Is Modifierfalse
                  Must Supportfalse
                  Summaryfalse
                  Alternate Namesinline resources, anonymous resources, contained resources
                  14. MessageHeader.extension
                  Definition

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

                  ShortAdditional content defined by implementations
                  Comments

                  There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                  Control0..*
                  TypeExtension
                  Is Modifierfalse
                  Must Supportfalse
                  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())
                  16. 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 managable, 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
                  Must Supportfalse
                  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
                  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.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 are defined by the implementation. Alternatively a canonical uri to the EventDefinition.

                  ShortEvent code or link to EventDefinition
                  Comments

                  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
                  BindingUnless not suitable, these codes SHALL be taken from AT Message Event Type ValueSet
                  (extensible to http://fhir.hl7.at/fhir/ATMessaging/0.1.0/ValueSet/at-messaging-event-type-vs)
                  TypeCoding
                  [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
                  Is Modifierfalse
                  Must Supportfalse
                  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()))
                  20. MessageHeader.event[x].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
                  22. MessageHeader.event[x].extension
                  Definition

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

                  ShortAdditional content defined by implementations
                  Comments

                  There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                  Control0..*
                  TypeExtension
                  Is Modifierfalse
                  Summaryfalse
                  Alternate Namesextensions, user content
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                  SlicingThis element introduces a set of slices on MessageHeader.event[x].extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
                  • value @ url
                  • 24. MessageHeader.event[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 be an absolute reference to some definition that establishes the system clearly and unambiguously.

                    Control1..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.

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

                    The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured, and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.

                    ShortVersion of the system - if relevant
                    Comments

                    Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.

                    NoteThis is a business version Id, not a resource version Id (see discussion)
                    Control0..1
                    Typestring
                    Is Modifierfalse
                    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()))
                    28. 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
                    Control1..1
                    This element is affected by the following invariants: cod-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()))
                    30. MessageHeader.event[x].display
                    Definition

                    A representation of the meaning of the code in the system, following the rules of the system.

                    ShortRepresentation defined by the system
                    Control0..1
                    This element is affected by the following invariants: cod-1
                    Typestring
                    Is Modifierfalse
                    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                    Summarytrue
                    Requirements

                    Need to be able to carry a human-readable meaning of the code for readers that do not know the system.

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

                    Indicates that this coding was chosen by a user directly - e.g. off a pick list of available items (codes or displays).

                    ShortIf this coding was chosen directly by the user
                    Comments

                    Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely.

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

                    This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing.

                    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                    34. 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.

                    Control1..1
                    TypeBackboneElement
                    Is Modifierfalse
                    Must Supportfalse
                    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()))
                    36. MessageHeader.destination.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
                    Typestring
                    Is Modifierfalse
                    XML FormatIn the XML format, this property is represented as an attribute.
                    Summaryfalse
                    38. MessageHeader.destination.extension
                    Definition

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

                    ShortAdditional content defined by implementations
                    Comments

                    There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                    Control0..*
                    TypeExtension
                    Is Modifierfalse
                    Summaryfalse
                    Alternate Namesextensions, user content
                    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                    ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                    40. 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 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. 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())
                    42. MessageHeader.destination.endpoint[x]
                    Definition

                    Indicates where the message should be routed.

                    ShortActual destination address or Endpoint resource
                    Comments

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

                    Control1..1
                    TypeReference(AT Messaging Endpoint)
                    [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
                    Is Modifierfalse
                    Must Supportfalse
                    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()))
                    44. MessageHeader.destination.name
                    Definition

                    Human-readable name for the target system.

                    ShortName of system
                    Control0..1
                    Typestring
                    Is Modifierfalse
                    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                    Must Supportfalse
                    Summarytrue
                    Requirements

                    May be used for routing of response and/or to support audit.

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

                    Identifies the target end system in situations where the initial message transmission is to an intermediary system.

                    ShortParticular delivery destination within the destination
                    Control0..1
                    TypeReference(Device)
                    Is Modifierfalse
                    Must Supportfalse
                    Summarytrue
                    Requirements

                    Supports multi-hop routing.

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

                    ShortIntended "real-world" recipient for the data
                    Control1..1
                    TypeReference(HL7® AT Core Practitioner Profile, HL7® AT Core PractitionerRole Profile, HL7® AT Core Organization Profile)
                    Is Modifierfalse
                    Must Supportfalse
                    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()))
                    50. MessageHeader.sender
                    Definition

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

                    ShortReal 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. Proposing to remove and rely on Task to convey this information.

                    Control0..1
                    TypeReference(HL7® AT Core Practitioner Profile, HL7® AT Core PractitionerRole Profile, HL7® AT Core Organization Profile)
                    Is Modifierfalse
                    Must Supportfalse
                    Obligations
                      ObligationsActor
                      SHOULD:populateSender Actor
                      SHALL:handleReceiver Actor
                      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()))
                      52. MessageHeader.author
                      Definition

                      The logical author of the message - the personor device that decided the described event should happen. When there is more than one candidate, pick the most proximal to the MessageHeader. Can provide other authors in extensions.

                      ShortThe source of the decision
                      Comments

                      Usually only for the request but can be used in a response.Proposing to remove and rely on Task to convey this information.

                      Control0..1
                      TypeReference(HL7® AT Core Practitioner Profile, HL7® AT Core PractitionerRole Profile, HL7® AT Core Organization Profile)
                      Is Modifierfalse
                      Must Supportfalse
                      Obligations
                        ObligationsActor
                        SHOULD:populateSender Actor
                        SHALL:handleReceiver Actor
                        Summarytrue
                        Requirements

                        Need to know for audit/traceback requirements and possibly for authorization.

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

                        The source application from which this message originated.

                        ShortMessage source application
                        Control1..1
                        TypeBackboneElement
                        Is Modifierfalse
                        Must Supportfalse
                        Summarytrue
                        Requirements

                        Allows replies, supports audit.

                        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                        56. MessageHeader.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
                        Typestring
                        Is Modifierfalse
                        XML FormatIn the XML format, this property is represented as an attribute.
                        Summaryfalse
                        58. MessageHeader.source.extension
                        Definition

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

                        ShortAdditional content defined by implementations
                        Comments

                        There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                        Control0..*
                        TypeExtension
                        Is Modifierfalse
                        Summaryfalse
                        Alternate Namesextensions, user content
                        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                        ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                        60. 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 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. 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())
                        62. MessageHeader.source.endpoint[x]
                        Definition

                        Identifies the routing target to send acknowledgements to.

                        ShortActual source address or Endpoint resource
                        Comments

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

                        Control1..1
                        TypeReference(AT Messaging Endpoint)
                        [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
                        Is Modifierfalse
                        Must Supportfalse
                        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()))
                        64. MessageHeader.source.name
                        Definition

                        Human-readable name for the source system.

                        ShortName of system
                        Control1..1
                        Typestring
                        Is Modifierfalse
                        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                        Must Supportfalse
                        Summarytrue
                        Requirements

                        May be used to support audit.

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

                        May include configuration or other information useful in debugging.

                        ShortName of software running the system
                        Control0..1
                        Typestring
                        Is Modifierfalse
                        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                        Must Supportfalse
                        Obligations
                          ObligationsActor
                          SHOULD:populateSender Actor
                          Summarytrue
                          Requirements

                          Supports audit and possibly interface engine behavior.

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

                          Can convey versions of multiple systems in situations where a message passes through multiple hands.

                          ShortVersion of software running
                          NoteThis is a business version Id, not a resource version Id (see discussion)
                          Control1..1
                          Typestring
                          Is Modifierfalse
                          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                          Must Supportfalse
                          Summarytrue
                          Requirements

                          Supports audit and possibly interface engine behavior.

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

                          An e-mail, phone, website or other contact point to use to resolve issues with message communications.

                          ShortHuman contact for problems
                          Control0..1
                          TypeContactPoint
                          Is Modifierfalse
                          Must Supportfalse
                          Obligations
                            ObligationsActor
                            SHOULD:populateSender Actor
                            Summarytrue
                            Requirements

                            Allows escalation of technical issues.

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

                            The person or organization that accepts overall responsibility for the contents of the message. The implication is that the message event happened under the policies of the responsible party.

                            ShortFinal responsibility for event
                            Comments

                            Usually only for the request but can be used in a response.Proposing to remove and rely on Task to convey this information.

                            Control0..1
                            TypeReference(Practitioner, PractitionerRole, Organization)
                            Is Modifierfalse
                            Must Supportfalse
                            Summarytrue
                            Requirements

                            Need to know for audit/traceback requirements and possibly for authorization.

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

                            Coded indication of the cause for the event - indicates a reason for the occurrence of the event that is a focus of this message.

                            ShortCause of event
                            Control0..1
                            BindingFor example codes, see ExampleMessageReasonCodes
                            (example to http://hl7.org/fhir/ValueSet/message-reason-encounter|5.0.0)

                            Reason for event occurrence.

                            TypeCodeableConcept
                            Is Modifierfalse
                            Must Supportfalse
                            Summarytrue
                            Requirements

                            Need to be able to track why resources are being changed and report in the audit log/history of the resource. May affect authorization.

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

                            Information about the message that this message is a response to. Only present if this message is a response.

                            ShortIf this is a reply to prior message
                            Control0..1
                            TypeBackboneElement
                            Is Modifierfalse
                            Must Supportfalse
                            Summarytrue
                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            78. MessageHeader.response.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
                            Typestring
                            Is Modifierfalse
                            XML FormatIn the XML format, this property is represented as an attribute.
                            Summaryfalse
                            80. MessageHeader.response.extension
                            Definition

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

                            ShortAdditional content defined by implementations
                            Comments

                            There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                            Control0..*
                            TypeExtension
                            Is Modifierfalse
                            Summaryfalse
                            Alternate Namesextensions, user content
                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                            82. MessageHeader.response.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 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. 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())
                            84. MessageHeader.response.identifier
                            Definition

                            The Bundle.identifier of the message to which this message is a response.

                            ShortBundle.identifier of original message
                            NoteThis is a business identifier, not a resource identifier (see discussion)
                            Control1..1
                            TypeIdentifier
                            Is Modifierfalse
                            Must Supportfalse
                            Summarytrue
                            Requirements

                            Allows receiver to know what message is being responded to.

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

                            Code that identifies the type of response to the message - whether it was successful or not, and whether it should be resent or not.

                            Shortok | transient-error | fatal-error
                            Comments

                            This is a generic response to the request message. Specific data for the response will be found in MessageHeader.focus.

                            Control1..1
                            BindingThe codes SHALL be taken from ResponseType
                            (required to http://hl7.org/fhir/ValueSet/response-code|5.0.0)

                            The kind of response to a message.

                            Typecode
                            Is Modifierfalse
                            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                            Must Supportfalse
                            Summarytrue
                            Requirements

                            Allows the sender of the acknowledge message to know if the request was successful or if action is needed.

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

                            Full details of any issues found in the message.

                            ShortSpecific list of hints/warnings/errors
                            Comments

                            This SHALL be contained in the bundle. If any of the issues are errors, the response code SHALL be an error.

                            Control0..1
                            TypeReference(OperationOutcome)
                            Is Modifierfalse
                            Must Supportfalse
                            Summarytrue
                            Requirements

                            Allows the sender of the message to determine what the specific issues are.

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

                            The actual data of the message - a reference to the root/focus class of the event. This is allowed to be a Parameters resource.

                            ShortThe actual content of the message
                            Comments

                            The data is defined where the transaction type is defined. The transaction data is always included in the bundle that is the full message. Only the root resource is specified. The resources it references should be contained in the bundle but are not also listed here. Multiple repetitions are allowed to cater for merges and other situations with multiple focal targets.

                            Control0..*
                            TypeReference(Resource)
                            Is Modifierfalse
                            Must Supportfalse
                            Summarytrue
                            Requirements

                            Every message event is about actual data, a single resource, that is identified in the definition of the event, and perhaps some or all linked resources.

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

                            Permanent link to the MessageDefinition for this message.

                            ShortLink to the definition for this message
                            Control1..1
                            Typecanonical(MessageDefinition)
                            Is Modifierfalse
                            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                            Must Supportfalse
                            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()))