HL7 FHIR® Implementation Guide: Electronic Case Reporting (eCR) - US Realm
2.1.2 - STU 2 United States of America flag

This page is part of the electronic Case Reporting (eCR) (v2.1.2: STU 2) 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: USPublicHealthMessageHeader - Detailed Descriptions

Active as of 2019-09-01

Definitions for the us-ph-messageheader resource profile.

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

0. MessageHeader
Definition

Sets expectations for supported capabilities for MessageHeader resource for public health.

ShortUS Public Health MessageHeader
Must Supportfalse
2. MessageHeader.extension:dataEncrypted
Slice NamedataEncrypted
Control0..1
TypeExtension(US Public Health Data Encrypted Extension) (Extension Type: boolean)
Must Supporttrue
4. MessageHeader.extension:messageProcessingCategory
Slice NamemessageProcessingCategory
Control1..1
TypeExtension(US Public Health Message Processing Category Extension) (Extension Type: code)
Must Supporttrue
6. MessageHeader.event[x]
ShortTypes of messages being sent between systems
Control1..1
BindingUnless not suitable, these codes SHALL be taken from US Public Health Message Types ValueSet
(extensible to http://hl7.org/fhir/us/ecr/ValueSet/us-ph-message-types-valueset)

US Public Health Message Types ValueSet

TypeCoding, uri
[x] NoteSeeChoice of Data Typesfor further information about how to use [x]
Must Supporttrue
8. MessageHeader.destination
Control1..*
Must Supporttrue
10. MessageHeader.destination.endpoint
Control1..1
Must Supporttrue
12. MessageHeader.sender
Control1..1
TypeReference(US Public Health Organization)
Must Supporttrue
14. MessageHeader.source
Control1..1
Must Supporttrue
16. MessageHeader.source.endpoint
Control1..1
Must Supporttrue
18. MessageHeader.reason
ShortThe named event that gave rise to the message
Control1..1
BindingUnless not suitable, these codes SHALL be taken from US Public Health TriggerDefinition NamedEvent
(extensible to http://hl7.org/fhir/us/ecr/ValueSet/us-ph-triggerdefinition-namedevent)

US Public Health TriggerDefinition NamedEvents

TypeCodeableConcept
Must Supporttrue
20. MessageHeader.response
Control0..1
Must Supporttrue
22. MessageHeader.response.identifier
NoteThis is a business identifier, not a resource identifier (see discussion)
Control1..1
Must Supporttrue
24. MessageHeader.response.code
Control1..1
Must Supporttrue
26. MessageHeader.response.details
Control0..1
Must Supporttrue

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

0. MessageHeader
Definition

Sets expectations for supported capabilities for MessageHeader resource for public health.


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.

ShortUS Public Health MessageHeaderA 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().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.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()))
4. MessageHeader.extension
Definition

An Extension


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 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.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
  • value @ url
  • 6. MessageHeader.extension:dataEncrypted
    Slice NamedataEncrypted
    Definition

    Indicates whether the data in the content bundle is encrypted or not.

    ShortUS Public Health Data Encrypted Extension
    Control0..1
    This element is affected by the following invariants: ele-1
    TypeExtension(US Public Health Data Encrypted Extension) (Extension Type: boolean)
    Is Modifierfalse
    Must Supporttrue
    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())
    8. MessageHeader.extension:messageProcessingCategory
    Slice NamemessageProcessingCategory
    Definition

    Indicates how systems have to deal with messages in terms of duplicates, lack of responses.

    ShortUS Public Health Message Processing Category Extension
    Control1..1
    This element is affected by the following invariants: ele-1
    TypeExtension(US Public Health Message Processing Category Extension) (Extension Type: code)
    Is Modifierfalse
    Must Supporttrue
    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())
    10. 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())
    12. 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.

    ShortTypes of messages being sent between systemsCode 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
    BindingUnless not suitable, these codes SHALL be taken from For example codes, see US Public Health Message Types ValueSethttp://hl7.org/fhir/ValueSet/message-events
    (extensible to http://hl7.org/fhir/us/ecr/ValueSet/us-ph-message-types-valueset)

    US Public Health Message Types ValueSet


    One of the message events defined as part of this version of FHIR.

    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()))
    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
    Must Supporttrue
    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()))
    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
    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()))
    20. 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.

    Control10..1
    TypeReference(US Public Health Organization, Practitioner, PractitionerRole, Organization)
    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()))
    22. MessageHeader.source
    Definition

    The source application from which this message originated.

    ShortMessage 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()))
    24. 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())
    26. 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()))
    28. 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.

    ShortThe named event that gave rise to the messageCause of event
    Control10..1
    BindingUnless not suitable, these codes SHALL be taken from For example codes, see US Public Health TriggerDefinition NamedEventhttp://hl7.org/fhir/ValueSet/message-reason-encounter
    (extensible to http://hl7.org/fhir/us/ecr/ValueSet/us-ph-triggerdefinition-namedevent)

    US Public Health TriggerDefinition NamedEvents


    Reason for event occurrence.

    TypeCodeableConcept
    Is Modifierfalse
    Must Supporttrue
    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()))
    30. 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 Supporttrue
    Summarytrue
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    32. 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 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())
    34. MessageHeader.response.identifier
    Definition

    The MessageHeader.id of the message to which this message is a response.

    ShortId of original message
    NoteThis is a business identifier, not a resource identifier (see discussion)
    Control1..1
    Typeid
    Is Modifierfalse
    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
    Must Supporttrue
    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()))
    36. 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 ResponseTypehttp://hl7.org/fhir/ValueSet/response-code|4.0.1
    (required to http://hl7.org/fhir/ValueSet/response-code|4.0.1)

    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 Supporttrue
    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()))
    38. 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 Supporttrue
    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()))

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

    0. MessageHeader
    Definition

    Sets expectations for supported capabilities for MessageHeader resource for public health.

    ShortUS Public Health MessageHeader
    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().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.

    ShortLogical 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.

    Control0..1
    Typeid
    Is Modifierfalse
    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
    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 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()))
    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 SHOULD be taken from CommonLanguages
    (preferred to http://hl7.org/fhir/ValueSet/languages)

    A human language.

    Additional BindingsPurpose
    AllLanguagesMax Binding
    Typecode
    Is Modifierfalse
    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
    Summaryfalse
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    10. 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 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
    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, and nor can they have their own independent transaction scope.

    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..*
    TypeResource
    Is Modifierfalse
    Summaryfalse
    Alternate Namesinline resources, anonymous resources, contained resources
    14. MessageHeader.extension
    Definition

    An Extension

    ShortExtension
    Control1..*
    TypeExtension
    Is Modifierfalse
    Summaryfalse
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
    SlicingThis element introduces a set of slices on MessageHeader.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
    • value @ url
    • 16. MessageHeader.extension:dataEncrypted
      Slice NamedataEncrypted
      Definition

      Indicates whether the data in the content bundle is encrypted or not.

      ShortUS Public Health Data Encrypted Extension
      Control0..1
      This element is affected by the following invariants: ele-1
      TypeExtension(US Public Health Data Encrypted Extension) (Extension Type: boolean)
      Is Modifierfalse
      Must Supporttrue
      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.extension:messageProcessingCategory
      Slice NamemessageProcessingCategory
      Definition

      Indicates how systems have to deal with messages in terms of duplicates, lack of responses.

      ShortUS Public Health Message Processing Category Extension
      Control1..1
      This element is affected by the following invariants: ele-1
      TypeExtension(US Public Health Message Processing Category Extension) (Extension Type: code)
      Is Modifierfalse
      Must Supporttrue
      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.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())
      22. 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.

      ShortTypes of messages being sent between systems
      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 US Public Health Message Types ValueSet
      (extensible to http://hl7.org/fhir/us/ecr/ValueSet/us-ph-message-types-valueset)

      US Public Health Message Types ValueSet

      TypeCoding
      [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()))
      24. 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..*
      TypeBackboneElement
      Is Modifierfalse
      Must Supporttrue
      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()))
      26. 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
      Typestring
      Is Modifierfalse
      XML FormatIn the XML format, this property is represented as an attribute.
      Summaryfalse
      28. 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 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.

      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())
      30. 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())
      32. 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
      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()))
      34. 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
      Summarytrue
      Requirements

      Supports multi-hop routing.

      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      36. 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
      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.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
      Control0..1
      TypeReference(Practitioner, PractitionerRole, Organization)
      Is Modifierfalse
      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.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.

      Control1..1
      TypeReference(US Public Health Organization)
      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()))
      42. MessageHeader.enterer
      Definition

      The person or device that performed the data entry leading to this message. When there is more than one candidate, pick the most proximal to the message. Can provide other enterers in extensions.

      ShortThe source of the data entry
      Comments

      Usually only for the request but can be used in a response.

      Control0..1
      TypeReference(Practitioner, PractitionerRole)
      Is Modifierfalse
      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()))
      44. MessageHeader.author
      Definition

      The logical author of the message - the person or 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.

      Control0..1
      TypeReference(Practitioner, PractitionerRole)
      Is Modifierfalse
      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()))
      46. MessageHeader.source
      Definition

      The source application from which this message originated.

      ShortMessage 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()))
      48. 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
      Typestring
      Is Modifierfalse
      XML FormatIn the XML format, this property is represented as an attribute.
      Summaryfalse
      50. 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 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.

      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())
      52. 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())
      54. MessageHeader.source.name
      Definition

      Human-readable name for the source system.

      ShortName of system
      Control0..1
      Typestring
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      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()))
      56. 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
      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()))
      58. 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)
      Control0..1
      Typestring
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      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()))
      60. 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
      Summarytrue
      Requirements

      Allows escalation of technical issues.

      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      62. 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()))
      64. 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.

      Control0..1
      TypeReference(Practitioner, PractitionerRole, Organization)
      Is Modifierfalse
      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()))
      66. 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.

      ShortThe named event that gave rise to the message
      Control1..1
      BindingUnless not suitable, these codes SHALL be taken from US Public Health TriggerDefinition NamedEvent
      (extensible to http://hl7.org/fhir/us/ecr/ValueSet/us-ph-triggerdefinition-namedevent)

      US Public Health TriggerDefinition NamedEvents

      TypeCodeableConcept
      Is Modifierfalse
      Must Supporttrue
      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()))
      68. 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 Supporttrue
      Summarytrue
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      70. 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
      Typestring
      Is Modifierfalse
      XML FormatIn the XML format, this property is represented as an attribute.
      Summaryfalse
      72. 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 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.

      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())
      74. 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 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())
      76. MessageHeader.response.identifier
      Definition

      The MessageHeader.id of the message to which this message is a response.

      ShortId of original message
      NoteThis is a business identifier, not a resource identifier (see discussion)
      Control1..1
      Typeid
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Must Supporttrue
      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()))
      78. 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|4.0.1)

      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 Supporttrue
      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()))
      80. 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 Supporttrue
      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()))
      82. MessageHeader.focus
      Definition

      The actual data of the message - a reference to the root/focus class of the event.

      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
      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()))
      84. 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
      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()))