Twiin Workflow
0.3.0-draft - Draft – normative only when referenced by the Twiin afsprakenstelsel

This page is part of the Twiin Workflow (v0.3.0-draft: Release 1 Draft) based on FHIR (HL7® FHIR® Standard) R4. No current official version has been published yet. For a full list of available versions, see the Directory of published versions

Resource Profile: Twiin Workflow Subscription - Detailed Descriptions

Draft as of 2026-10-16

Definitions for the twiin-workflow-subscription resource profile

See the documentation on how to interpret the contents of this table

0. Subscription
Definition

The subscription resource is used to define a push-based subscription from a server to another system. Once a subscription is registered with the server, the server checks every resource that is created or updated, and if the resource matches the given criteria, it sends a message on the defined "channel" so that another system can take an appropriate action.

ShortServer push subscription criteria
Control0..*
Is Modifierfalse
Must Supportfalse
Summaryfalse
Alternate NamesWebHook, Hook, Routing Rule
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.exists() and ('#'+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(uri) = '#').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())
twiin-sub-1: criteria is the canonical URL of a SubscriptionTopic: an http(s) URL without a query. This is a heuristic to catch an R4 search expression in criteria. (criteria.matches('^https?://[^?]+$'))
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())
2. Subscription.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
Must Supportfalse
Summarytrue
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
4. Subscription.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
Must Supportfalse
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())
6. Subscription.status
Definition

The status of the subscription, which marks the server state for managing the subscription.

Shortrequested | active | error | off
Comments

A client can only submit subscription resources in the requested or off state. Only the server can move a subscription from requested to active, and then to error. Either the server or the client can turn a subscription off.

This element is labeled as a modifier because the status contains codes that mark the resource as not currently valid.

Control1..1
BindingThe codes SHALL be taken from SubscriptionStatushttp://hl7.org/fhir/ValueSet/subscription-status|4.0.1
(required to http://hl7.org/fhir/ValueSet/subscription-status|4.0.0)

The status of a subscription.

Typecode
Is Modifiertrue because This element is labelled as a modifier because it is a status element that contains status entered-in-error which means that the resource should not be treated as valid
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. Subscription.reason
Definition

A description of why this subscription is defined.

ShortDescription of why this subscription was created
Control1..1
Typestring
Is Modifierfalse
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()))
10. Subscription.criteria
Definition

When using topic-based subscriptions, the primary criteria is always the topic, indicated by its canonical URL.


The rules that the server should use to determine when to generate notifications for this subscription.

ShortCanonical URL for the topic used to generate eventsRule for server push
Comments

The rules are search criteria (without the [base] part). Like Bundle.entry.request.url, it has no leading "/".

Control1..1
Typestring
Is Modifierfalse
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
12. Subscription.criteria.extension
Definition

An Extension


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

ShortExtensionAdditional content defined by implementations
Comments

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

Control10..*
TypeExtension
Is Modifierfalse
Summaryfalse
Alternate Namesextensions, user content
Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
SlicingThis element introduces a set of slices on Subscription.criteria.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
  • value @ url
  • Slicing Note: The rules on this element (including its children) apply to all the slices, but are not repeated in them

    14. Subscription.criteria.extension:filterCriteria
    Slice NamefilterCriteria
    Definition

    Criteria for topic-based filtering (filter-by).

    ShortBackported R5 FilterBy Criteria
    Control1..1
    This element is affected by the following invariants: ele-1
    TypeExtension(Backported R5 FilterBy Criteria) (Extension Type: string)
    Is Modifierfalse
    Must Supporttrue
    Summarytrue
    Invariantsele-1: All FHIR elements must have a @value or children unless an empty Parameters resource (hasValue() or (children().count() > id.count()) or $this is Parameters)
    ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
    twiin-wsub-1: The filter is of the form owner:identifier=[system]|[value] (TA section Subscription). (value.ofType(string).matches('^owner:identifier=[^|\\s]+[|][^|\\s]+$'))
    ele-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. Subscription.channel
    Definition

    Details where to send notifications when resources are received that meet the criteria.

    ShortThe channel on which to report matches to the criteria
    Control1..1
    TypeBackboneElement
    Is Modifierfalse
    Must Supportfalse
    Summarytrue
    Invariantsele-1: All FHIR elements must have a @value or children unless an empty Parameters resource (hasValue() or (children().count() > id.count()) or $this is Parameters)
    ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    18. Subscription.channel.extension
    Definition

    An Extension


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

    ShortExtensionAdditional content defined by implementations
    Comments

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

    Control10..*
    TypeExtension
    Is Modifierfalse
    Summaryfalse
    Alternate Namesextensions, user content
    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
    ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
    SlicingThis element introduces a set of slices on Subscription.channel.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
    • value @ url
    • Slicing Note: The rules on this element (including its children) apply to all the slices, but are not repeated in them

      20. Subscription.channel.extension:heartbeatPeriod
      Slice NameheartbeatPeriod
      Definition

      Interval in seconds to send 'heartbeat' notifications.

      ShortBackport R5 Subscription Heartbeat Period
      Control1..1
      This element is affected by the following invariants: ele-1
      TypeExtension(Backport R5 Subscription Heartbeat Period) (Extension Type: unsignedInt)
      Is Modifierfalse
      Invariantsele-1: All FHIR elements must have a @value or children unless an empty Parameters resource (hasValue() or (children().count() > id.count()) or $this is Parameters)
      ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
      ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
      22. Subscription.channel.extension:timeout
      Slice Nametimeout
      Definition

      If present, the maximum amount of time a server will allow before failing a notification attempt.

      ShortTimeout in seconds to attempt notification delivery
      Control0..1
      This element is affected by the following invariants: ele-1
      TypeExtension(Backport R5 Subscription Timeout) (Extension Type: unsignedInt)
      Is Modifierfalse
      Invariantsele-1: All FHIR elements must have a @value or children unless an empty Parameters resource (hasValue() or (children().count() > id.count()) or $this is Parameters)
      ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
      ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
      24. Subscription.channel.extension:maxCount
      Slice NamemaxCount
      Definition

      If present, the maximum number of triggering resources that will be included in a notification bundle (e.g., a server will not include more than this number of trigger resources in a single notification). Note that this is not a strict limit on the number of entries in a bundle, as dependent resources can be included.

      ShortMaximum number of triggering resources included in notification bundles
      Control0..1
      This element is affected by the following invariants: ele-1
      TypeExtension(Backported R5 Subscription MaxCount) (Extension Type: positiveInt)
      Is Modifierfalse
      Invariantsele-1: All FHIR elements must have a @value or children unless an empty Parameters resource (hasValue() or (children().count() > id.count()) or $this is Parameters)
      ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
      ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
      26. Subscription.channel.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())
      28. Subscription.channel.type
      Definition

      The type of channel to send notifications on.

      Shortrest-hook | websocket | email | sms | message
      Control1..1
      BindingThe codes SHALL be taken from SubscriptionChannelTypehttp://hl7.org/fhir/ValueSet/subscription-channel-type|4.0.1
      (required to http://hl7.org/fhir/ValueSet/subscription-channel-type|4.0.0)

      The type of method used to execute a subscription.

      Typecode
      Is Modifierfalse
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Must Supportfalse
      Summarytrue
      Pattern Valuerest-hook
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      30. Subscription.channel.type.extension:customChannelType
      Slice NamecustomChannelType
      Definition

      The type of channel to send notifications on.

      ShortExtended channel type for notifications
      Comments

      This extension allows for the use of additional channel types that were not defined in the FHIR R4 subscription definition.

      Control0..1
      This element is affected by the following invariants: ele-1
      TypeExtension(Backported R5 Additional Channel Types) (Extension Type: Coding)
      Is Modifierfalse
      Must Supporttrue
      Summarytrue
      Invariantsele-1: All FHIR elements must have a @value or children unless an empty Parameters resource (hasValue() or (children().count() > id.count()) or $this is Parameters)
      ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
      ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
      32. Subscription.channel.endpoint
      Definition

      The url that describes the actual end-point to send messages to.

      ShortWhere the channel points to
      Comments

      For rest-hook, and websocket, the end-point must be an http: or https: URL; for email, a mailto: url, for sms, a tel: url, and for message the endpoint can be in any form of url the server understands (usually, http: or mllp:). The URI is allowed to be relative; in which case, it is relative to the server end-point (since there may be more than one, clients should avoid using relative URIs).

      Control10..1
      Typeurl
      Is Modifierfalse
      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()))
      34. Subscription.channel.payload
      Definition

      The mime type to send the payload in - either application/fhir+xml, or application/fhir+json. If the payload is not present, then there is no payload in the notification, just a notification. The mime type "text/plain" may also be used for Email and SMS subscriptions.

      ShortMIME type to send, or omit for no payload
      Comments

      Sending the payload has obvious security implications. The server is responsible for ensuring that the content is appropriately secured.

      Control10..1
      BindingThe codes SHALL be taken from Twiin Notification Formatshttp://hl7.org/fhir/ValueSet/mimetypes|4.0.1
      (required to https://fhir.twiin.nl/ig/notifications/ValueSet/twiin-notification-formats)
      Typecode
      Is Modifierfalse
      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()))
      36. Subscription.channel.payload.extension
      Definition

      An Extension


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

      ShortExtensionAdditional content defined by implementations
      Comments

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

      Control10..*
      TypeExtension
      Is Modifierfalse
      Summaryfalse
      Alternate Namesextensions, user content
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
      ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
      SlicingThis element introduces a set of slices on Subscription.channel.payload.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
      • value @ url
      • 38. Subscription.channel.payload.extension:content
        Slice Namecontent
        Definition

        How much of the resource content to deliver in the notification payload. The choices are an empty payload, only the resource id, or the full resource content.

        ShortBackport R5 Subscription Payload Content Information
        Control1..1
        This element is affected by the following invariants: ele-1
        TypeExtension(Backport R5 Subscription Payload Content Information) (Extension Type: code)
        Is Modifierfalse
        Must Supporttrue
        Summarytrue
        Invariantsele-1: All FHIR elements must have a @value or children unless an empty Parameters resource (hasValue() or (children().count() > id.count()) or $this is Parameters)
        ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
        ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
        40. Subscription.channel.payload.extension:content.extension
        Definition

        An Extension


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

        ShortExtensionAdditional content defined by implementations
        Comments

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

        Control0..0*
        TypeExtension
        Is Modifierfalse
        Summaryfalse
        Alternate Namesextensions, user content
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
        SlicingThis element introduces a set of slices on Subscription.channel.payload.extension.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
        • value @ url
        • 42. Subscription.channel.payload.extension:content.url
          Definition

          Source of the definition for the extension code - a logical name or a URL.

          Shortidentifies the meaning of the extension
          Comments

          The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

          Control1..1
          Typeuri
          Is Modifierfalse
          XML FormatIn the XML format, this property is represented as an attribute.
          Summaryfalse
          Fixed Valuehttp://hl7.org/fhir/uv/subscriptions-backport/StructureDefinition/backport-payload-content
          44. Subscription.channel.payload.extension:content.value[x]
          Definition

          How much of the resource content to deliver in the notification payload. The choices are an empty payload, only the resource id, or the full resource content.


          Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

          ShortNotification content levelValue of extension
          Comments

          Sending the payload has obvious security implications. The server is responsible for ensuring that the content is appropriately secured.

          Control0..1
          Typecode, date, Meta, Address, Attachment, integer, Count, DataRequirement, Dosage, uuid, Identifier, Coding, SampledData, id, positiveInt, Distance, Period, Duration, canonical, Range, RelatedArtifact, base64Binary, UsageContext, Timing, decimal, CodeableConcept, ParameterDefinition, dateTime, string, Contributor, oid, instant, ContactPoint, HumanName, Money, markdown, Ratio, Age, Reference, TriggerDefinition, Quantity, uri, url, Annotation, ContactDetail, boolean, Expression, Signature, unsignedInt, time
          [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
          Is Modifierfalse
          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()))
          SlicingThis element introduces a set of slices on Subscription.channel.payload.extension.value[x]. The slices areUnordered and Closed, and can be differentiated using the following discriminators:
          • type @ $this
          • 46. Subscription.channel.payload.extension:content.value[x]:valueCode
            Slice NamevalueCode
            Definition

            Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

            ShortValue of extension
            Control0..1
            BindingThe codes SHALL be taken from For codes, see Backported R5 Subscription Content Value Set
            (required to http://hl7.org/fhir/uv/subscriptions-backport/ValueSet/backport-content-value-set)
            Typecode, date, Meta, Address, Attachment, integer, Count, DataRequirement, Dosage, uuid, Identifier, Coding, SampledData, id, positiveInt, Distance, Period, Duration, canonical, Range, RelatedArtifact, base64Binary, UsageContext, Timing, decimal, CodeableConcept, ParameterDefinition, dateTime, string, Contributor, oid, instant, ContactPoint, HumanName, Money, markdown, Ratio, Age, Reference, TriggerDefinition, Quantity, uri, url, Annotation, ContactDetail, boolean, Expression, Signature, unsignedInt, time
            [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
            Is Modifierfalse
            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
            Summaryfalse
            Pattern Valueid-only
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))

            See the documentation on how to interpret the contents of this table

            0. Subscription
            2. Subscription.criteria
            4. Subscription.criteria.extension
            Control1..?
            6. Subscription.criteria.extension:filterCriteria
            Slice NamefilterCriteria
            Control1..1
            Invariantstwiin-wsub-1: The filter is of the form owner:identifier=[system]|[value] (TA section Subscription). (value.ofType(string).matches('^owner:identifier=[^|\\s]+[|][^|\\s]+$'))
            8. Subscription.channel
            10. Subscription.channel.extension
            Control1..?
            12. Subscription.channel.extension:heartbeatPeriod
            Slice NameheartbeatPeriod
            Control1..?
            14. Subscription.channel.payload
            16. Subscription.channel.payload.extension:content
            Slice Namecontent
            18. Subscription.channel.payload.extension:content.value[x]:valueCode
            Slice NamevalueCode
            Typecode
            [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
            Pattern Valueid-only

            See the documentation on how to interpret the contents of this table

            0. Subscription
            Definition

            The subscription resource is used to define a push-based subscription from a server to another system. Once a subscription is registered with the server, the server checks every resource that is created or updated, and if the resource matches the given criteria, it sends a message on the defined "channel" so that another system can take an appropriate action.

            ShortServer push subscription criteria
            Control0..*
            Is Modifierfalse
            Must Supportfalse
            Summaryfalse
            Alternate NamesWebHook, Hook, Routing Rule
            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.exists() and ('#'+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(uri) = '#').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())
            twiin-sub-1: criteria is the canonical URL of a SubscriptionTopic: an http(s) URL without a query. This is a heuristic to catch an R4 search expression in criteria. (criteria.matches('^https?://[^?]+$'))
            2. Subscription.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
            Must Supportfalse
            Summarytrue
            4. Subscription.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. Subscription.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
            Must Supportfalse
            Summarytrue
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            8. Subscription.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)

            IETF language tag

            Additional BindingsPurpose
            AllLanguagesMax Binding
            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. Subscription.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
            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. Subscription.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
            Must Supportfalse
            Summaryfalse
            Alternate Namesinline resources, anonymous resources, contained resources
            Invariantsdom-r4b: Containing new R4B resources within R4 resources may cause interoperability issues if instances are shared with R4 systems (($this is Citation or $this is Evidence or $this is EvidenceReport or $this is EvidenceVariable or $this is MedicinalProductDefinition or $this is PackagedProductDefinition or $this is AdministrableProductDefinition or $this is Ingredient or $this is ClinicalUseDefinition or $this is RegulatedAuthorization or $this is SubstanceDefinition or $this is SubscriptionStatus or $this is SubscriptionTopic) implies (%resource is Citation or %resource is Evidence or %resource is EvidenceReport or %resource is EvidenceVariable or %resource is MedicinalProductDefinition or %resource is PackagedProductDefinition or %resource is AdministrableProductDefinition or %resource is Ingredient or %resource is ClinicalUseDefinition or %resource is RegulatedAuthorization or %resource is SubstanceDefinition or %resource is SubscriptionStatus or %resource is SubscriptionTopic))
            14. Subscription.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 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
            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. Subscription.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
            Must Supportfalse
            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())
            18. Subscription.status
            Definition

            The status of the subscription, which marks the server state for managing the subscription.

            Shortrequested | active | error | off
            Comments

            A client can only submit subscription resources in the requested or off state. Only the server can move a subscription from requested to active, and then to error. Either the server or the client can turn a subscription off.

            This element is labeled as a modifier because the status contains codes that mark the resource as not currently valid.

            Control1..1
            BindingThe codes SHALL be taken from SubscriptionStatus
            (required to http://hl7.org/fhir/ValueSet/subscription-status|4.0.0)

            The status of a subscription.

            Typecode
            Is Modifiertrue because This element is labelled as a modifier because it is a status element that contains status entered-in-error which means that the resource should not be treated as valid
            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()))
            20. Subscription.contact
            Definition

            Contact details for a human to contact about the subscription. The primary use of this for system administrator troubleshooting.

            ShortContact details for source (e.g. troubleshooting)
            Control0..*
            TypeContactPoint
            Is Modifierfalse
            Must Supportfalse
            Summarytrue
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            22. Subscription.end
            Definition

            The time for the server to turn the subscription off.

            ShortWhen to automatically delete the subscription
            Comments

            The server is permitted to deviate from this time but should observe it.

            Control0..1
            Typeinstant
            Is Modifierfalse
            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()))
            24. Subscription.reason
            Definition

            A description of why this subscription is defined.

            ShortDescription of why this subscription was created
            Control1..1
            Typestring
            Is Modifierfalse
            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()))
            26. Subscription.criteria
            Definition

            When using topic-based subscriptions, the primary criteria is always the topic, indicated by its canonical URL.

            ShortCanonical URL for the topic used to generate events
            Comments

            The rules are search criteria (without the [base] part). Like Bundle.entry.request.url, it has no leading "/".

            Control1..1
            Typestring
            Is Modifierfalse
            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
            Must Supporttrue
            Summarytrue
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            28. Subscription.criteria.id
            Definition

            unique id for the element within a resource (for internal references)

            Shortxml:id (or equivalent in JSON)
            Control0..1
            Typestring
            Is Modifierfalse
            XML FormatIn the XML format, this property is represented as an attribute.
            Summaryfalse
            30. Subscription.criteria.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 Subscription.criteria.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
            • value @ url
            • Slicing Note: The rules on this element (including its children) apply to all the slices, but are not repeated in them

              32. Subscription.criteria.extension:filterCriteria
              Slice NamefilterCriteria
              Definition

              Criteria for topic-based filtering (filter-by).

              ShortBackported R5 FilterBy Criteria
              Control1..1
              This element is affected by the following invariants: ele-1
              TypeExtension(Backported R5 FilterBy Criteria) (Extension Type: string)
              Is Modifierfalse
              Must Supporttrue
              Summarytrue
              Invariantsele-1: All FHIR elements must have a @value or children unless an empty Parameters resource (hasValue() or (children().count() > id.count()) or $this is Parameters)
              ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
              twiin-wsub-1: The filter is of the form owner:identifier=[system]|[value] (TA section Subscription). (value.ofType(string).matches('^owner:identifier=[^|\\s]+[|][^|\\s]+$'))
              34. Subscription.criteria.value
              Definition

              The actual value

              ShortPrimitive value for string
              Control0..1
              Typestring
              Is Modifierfalse
              XML FormatIn the XML format, this property is represented as an attribute.
              Summaryfalse
              Max Length:1048576
              36. Subscription.error
              Definition

              A record of the last error that occurred when the server processed a notification.

              ShortLatest error note
              Control0..1
              Typestring
              Is Modifierfalse
              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()))
              38. Subscription.channel
              Definition

              Details where to send notifications when resources are received that meet the criteria.

              ShortThe channel on which to report matches to the criteria
              Control1..1
              TypeBackboneElement
              Is Modifierfalse
              Must Supportfalse
              Summarytrue
              Invariantsele-1: All FHIR elements must have a @value or children unless an empty Parameters resource (hasValue() or (children().count() > id.count()) or $this is Parameters)
              40. Subscription.channel.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
              42. Subscription.channel.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 Subscription.channel.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
              • value @ url
              • Slicing Note: The rules on this element (including its children) apply to all the slices, but are not repeated in them

                44. Subscription.channel.extension:heartbeatPeriod
                Slice NameheartbeatPeriod
                Definition

                Interval in seconds to send 'heartbeat' notifications.

                ShortBackport R5 Subscription Heartbeat Period
                Control1..1
                This element is affected by the following invariants: ele-1
                TypeExtension(Backport R5 Subscription Heartbeat Period) (Extension Type: unsignedInt)
                Is Modifierfalse
                Invariantsele-1: All FHIR elements must have a @value or children unless an empty Parameters resource (hasValue() or (children().count() > id.count()) or $this is Parameters)
                ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                46. Subscription.channel.extension:timeout
                Slice Nametimeout
                Definition

                If present, the maximum amount of time a server will allow before failing a notification attempt.

                ShortTimeout in seconds to attempt notification delivery
                Control0..1
                This element is affected by the following invariants: ele-1
                TypeExtension(Backport R5 Subscription Timeout) (Extension Type: unsignedInt)
                Is Modifierfalse
                Invariantsele-1: All FHIR elements must have a @value or children unless an empty Parameters resource (hasValue() or (children().count() > id.count()) or $this is Parameters)
                ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                48. Subscription.channel.extension:maxCount
                Slice NamemaxCount
                Definition

                If present, the maximum number of triggering resources that will be included in a notification bundle (e.g., a server will not include more than this number of trigger resources in a single notification). Note that this is not a strict limit on the number of entries in a bundle, as dependent resources can be included.

                ShortMaximum number of triggering resources included in notification bundles
                Control0..1
                This element is affected by the following invariants: ele-1
                TypeExtension(Backported R5 Subscription MaxCount) (Extension Type: positiveInt)
                Is Modifierfalse
                Invariantsele-1: All FHIR elements must have a @value or children unless an empty Parameters resource (hasValue() or (children().count() > id.count()) or $this is Parameters)
                ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                50. Subscription.channel.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())
                52. Subscription.channel.type
                Definition

                The type of channel to send notifications on.

                Shortrest-hook | websocket | email | sms | message
                Control1..1
                BindingThe codes SHALL be taken from SubscriptionChannelType
                (required to http://hl7.org/fhir/ValueSet/subscription-channel-type|4.0.0)

                The type of method used to execute a subscription.

                Typecode
                Is Modifierfalse
                Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                Must Supportfalse
                Summarytrue
                Pattern Valuerest-hook
                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                54. Subscription.channel.type.id
                Definition

                unique id for the element within a resource (for internal references)

                Shortxml:id (or equivalent in JSON)
                Control0..1
                Typestring
                Is Modifierfalse
                XML FormatIn the XML format, this property is represented as an attribute.
                Summaryfalse
                56. Subscription.channel.type.extension
                Definition

                An Extension

                ShortExtension
                Control0..*
                TypeExtension
                Is Modifierfalse
                Summaryfalse
                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                SlicingThis element introduces a set of slices on Subscription.channel.type.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
                • value @ url
                • 58. Subscription.channel.type.extension:customChannelType
                  Slice NamecustomChannelType
                  Definition

                  The type of channel to send notifications on.

                  ShortExtended channel type for notifications
                  Comments

                  This extension allows for the use of additional channel types that were not defined in the FHIR R4 subscription definition.

                  Control0..1
                  This element is affected by the following invariants: ele-1
                  TypeExtension(Backported R5 Additional Channel Types) (Extension Type: Coding)
                  Is Modifierfalse
                  Must Supporttrue
                  Summarytrue
                  Invariantsele-1: All FHIR elements must have a @value or children unless an empty Parameters resource (hasValue() or (children().count() > id.count()) or $this is Parameters)
                  ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                  60. Subscription.channel.type.value
                  Definition

                  Primitive value for code

                  ShortPrimitive value for code
                  Control0..1
                  Typecode
                  Is Modifierfalse
                  XML FormatIn the XML format, this property is represented as an attribute.
                  Summaryfalse
                  62. Subscription.channel.endpoint
                  Definition

                  The url that describes the actual end-point to send messages to.

                  ShortWhere the channel points to
                  Comments

                  For rest-hook, and websocket, the end-point must be an http: or https: URL; for email, a mailto: url, for sms, a tel: url, and for message the endpoint can be in any form of url the server understands (usually, http: or mllp:). The URI is allowed to be relative; in which case, it is relative to the server end-point (since there may be more than one, clients should avoid using relative URIs).

                  Control1..1
                  Typeurl
                  Is Modifierfalse
                  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()))
                  64. Subscription.channel.payload
                  Definition

                  The mime type to send the payload in - either application/fhir+xml, or application/fhir+json. If the payload is not present, then there is no payload in the notification, just a notification. The mime type "text/plain" may also be used for Email and SMS subscriptions.

                  ShortMIME type to send, or omit for no payload
                  Comments

                  Sending the payload has obvious security implications. The server is responsible for ensuring that the content is appropriately secured.

                  Control1..1
                  BindingThe codes SHALL be taken from Twiin Notification Formats
                  (required to https://fhir.twiin.nl/ig/notifications/ValueSet/twiin-notification-formats)
                  Typecode
                  Is Modifierfalse
                  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()))
                  66. Subscription.channel.payload.id
                  Definition

                  unique id for the element within a resource (for internal references)

                  Shortxml:id (or equivalent in JSON)
                  Control0..1
                  Typestring
                  Is Modifierfalse
                  XML FormatIn the XML format, this property is represented as an attribute.
                  Summaryfalse
                  68. Subscription.channel.payload.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 Subscription.channel.payload.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
                  • value @ url
                  • 70. Subscription.channel.payload.extension:content
                    Slice Namecontent
                    Definition

                    How much of the resource content to deliver in the notification payload. The choices are an empty payload, only the resource id, or the full resource content.

                    ShortBackport R5 Subscription Payload Content Information
                    Control1..1
                    This element is affected by the following invariants: ele-1
                    TypeExtension(Backport R5 Subscription Payload Content Information) (Extension Type: code)
                    Is Modifierfalse
                    Must Supporttrue
                    Summarytrue
                    Invariantsele-1: All FHIR elements must have a @value or children unless an empty Parameters resource (hasValue() or (children().count() > id.count()) or $this is Parameters)
                    ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                    72. Subscription.channel.payload.extension:content.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
                    Typeid
                    Is Modifierfalse
                    XML FormatIn the XML format, this property is represented as an attribute.
                    Summaryfalse
                    74. Subscription.channel.payload.extension:content.extension
                    Definition

                    An Extension

                    ShortExtension
                    Control0..0
                    TypeExtension
                    Is Modifierfalse
                    Summaryfalse
                    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                    ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                    SlicingThis element introduces a set of slices on Subscription.channel.payload.extension.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
                    • value @ url
                    • 76. Subscription.channel.payload.extension:content.url
                      Definition

                      Source of the definition for the extension code - a logical name or a URL.

                      Shortidentifies the meaning of the extension
                      Comments

                      The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

                      Control1..1
                      Typeuri
                      Is Modifierfalse
                      XML FormatIn the XML format, this property is represented as an attribute.
                      Summaryfalse
                      Fixed Valuehttp://hl7.org/fhir/uv/subscriptions-backport/StructureDefinition/backport-payload-content
                      78. Subscription.channel.payload.extension:content.value[x]
                      Definition

                      How much of the resource content to deliver in the notification payload. The choices are an empty payload, only the resource id, or the full resource content.

                      ShortNotification content level
                      Comments

                      Sending the payload has obvious security implications. The server is responsible for ensuring that the content is appropriately secured.

                      Control0..1
                      Typecode
                      [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
                      Is Modifierfalse
                      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                      Summaryfalse
                      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                      SlicingThis element introduces a set of slices on Subscription.channel.payload.extension.value[x]. The slices areUnordered and Closed, and can be differentiated using the following discriminators:
                      • type @ $this
                      • 80. Subscription.channel.payload.extension:content.value[x]:valueCode
                        Slice NamevalueCode
                        Definition

                        Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

                        ShortValue of extension
                        Control0..1
                        BindingThe codes SHALL be taken from Backported R5 Subscription Content Value Set
                        (required to http://hl7.org/fhir/uv/subscriptions-backport/ValueSet/backport-content-value-set)
                        Typecode
                        [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
                        Is Modifierfalse
                        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                        Summaryfalse
                        Pattern Valueid-only
                        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                        82. Subscription.channel.payload.value
                        Definition

                        Primitive value for code

                        ShortPrimitive value for code
                        Control0..1
                        Typecode
                        Is Modifierfalse
                        XML FormatIn the XML format, this property is represented as an attribute.
                        Summaryfalse
                        84. Subscription.channel.header
                        Definition

                        Additional headers / information to send as part of the notification.

                        ShortUsage depends on the channel type
                        Comments

                        Exactly what these mean depend on the channel type. They can convey additional information to the recipient and/or meet security requirements; for example, support of multiple headers in the outgoing notifications for rest-hook type subscriptions.

                        Control0..*
                        Typestring
                        Is Modifierfalse
                        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()))