CH EPR mHealth (R4)
3.0.0-ballot - ballot Switzerland flag

This page is part of the CH EPR mHealth (R4) (v3.0.0-ballot: Draft Ballot 1) based on FHIR R4. This is the current published version in its permanent home (it will always be available at this URL). For a full list of available versions, see the Directory of published versions

Resource Profile: CHMhdDocumentReferenceComprehensive - Detailed Descriptions

Draft as of 2020-07-10

Definitions for the ch-mhd-documentreference-comprehensive resource profile.

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

1. DocumentReference
InvariantsDefined on this element
ch-mhd: The DocumentReference needs to conform to IHE.MHD.Comprehensive.DocumentReference (: conformsTo('https://profiles.ihe.net/ITI/MHD/StructureDefinition/IHE.MHD.Comprehensive.DocumentReference'))
2. DocumentReference.extension
Control10..*
Must Supporttrue
SlicingThis element introduces a set of slices on DocumentReference.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
3. DocumentReference.extension:deletionStatus
SliceNamedeletionStatus
Control0..1
TypeExtension(ChExtDeletionStatus) (Extension Type: Coding)
Must Supporttrue
4. DocumentReference.extension:originalProviderRole
SliceNameoriginalProviderRole
Control1..1
TypeExtension(ChExtAuthorAuthorRole) (Extension Type: Coding)
Must Supporttrue
5. DocumentReference.masterIdentifier
Control10..1
TypeIdentifier(OidIdentifier)
Must Supporttrue
Comments

See ITI TF-2: Z.9.1.1 Identifier and CDA root plus extension.

CDA Document Id extension and root.

6. DocumentReference.identifier
NoteThis is a business identifier, not a resource identifier (see discussion)
Must Supporttrue
7. DocumentReference.status
Must Supporttrue
Comments

approved -> status=current, deprecated -> status=superseded

This is the status of the DocumentReference object, which might be independent from the docStatus element.

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

8. DocumentReference.docStatus
Control0..01
Comments

These HL7 FHIR elements are not used in XDS, therefore would not be present. Document Consumers should be robust to these elements holding values.

The document that is pointed to might be in various lifecycle states.

9. DocumentReference.type
Control10..1
Must Supporttrue
10. DocumentReference.category
Control10..1*
Must Supporttrue
11. DocumentReference.subject
Control10..1
TypeReference(CHCorePatient|CHCorePractitioner|Group|Device) : {r}
Must Supporttrue
Comments

Not a contained resource. URL Points to an existing Patient Resource representing the XDS Affinity Domain Patient.

12. DocumentReference.date
Control10..1
Must Supporttrue
13. DocumentReference.author
Type : {c}
Must Supporttrue
Comments

Contained resource.

Not necessarily who did the actual data entry (i.e. typist) or who was the source (informant).

14. DocumentReference.authenticator
Type : {c}
15. DocumentReference.custodian
Control0..01
16. DocumentReference.relatesTo
Must Supporttrue
Comments

See ITI TF-2c: 3.65.4.1.2.3

This element is labeled as a modifier because documents that append to other documents are incomplete on their own.

17. DocumentReference.description
Must Supporttrue
18. DocumentReference.securityLabel
Control10..*
Must Supporttrue
Comments

Note: This is NOT the DocumentReference.meta, as that holds the meta tags for the DocumentReference itself.

The confidentiality codes can carry multiple vocabulary items. HL7 has developed an understanding of security and privacy tags that might be desirable in a Document Sharing environment, called HL7 Healthcare Privacy and Security Classification System (HCS). The following specification is recommended but not mandated, as the vocabulary bindings are an administrative domain responsibility. The use of this method is up to the policy domain such as the XDS Affinity Domain or other Trust Domain where all parties including sender and recipients are trusted to appropriately tag and enforce.

In the HL7 Healthcare Privacy and Security Classification (HCS) there are code systems specific to Confidentiality, Sensitivity, Integrity, and Handling Caveats. Some values would come from a local vocabulary as they are related to workflow roles and special projects.

19. DocumentReference.content
Control1..1*
20. DocumentReference.content.attachment
Must Supporttrue
21. DocumentReference.content.attachment.contentType
Control10..1
BindingThe codes SHALL be taken from DocumentEntry.mimeTypeThe codes SHALL be taken from Mime Types
Must Supporttrue
22. DocumentReference.content.attachment.language
Control10..1
BindingThe codes SHALL be taken from DocumentEntry.languageCodeThe codes SHOULD be taken from DocumentEntry.languageCode
Must Supporttrue
23. DocumentReference.content.attachment.data
Control0..01
Comments

These HL7 FHIR elements are not used in XDS, therefore would not be present. Document Consumers should be robust to these elements holding values.

The base64-encoded data SHALL be expressed in the same character set as the base resource XML or JSON.

24. DocumentReference.content.attachment.url
Control10..1
Must Supporttrue
25. DocumentReference.content.attachment.size
Must Supporttrue
26. DocumentReference.content.attachment.hash
Must Supporttrue
27. DocumentReference.content.attachment.title
Must Supporttrue
28. DocumentReference.content.attachment.creation
Control10..1
Must Supporttrue
29. DocumentReference.content.format
Control10..1
BindingThe codes SHALL be taken from DocumentEntry.formatCodeThe codes SHOULD be taken from DocumentEntry.formatCode Document Format Codes
Must Supporttrue
30. DocumentReference.context
Control10..1
31. DocumentReference.context.period
Must Supporttrue
32. DocumentReference.context.facilityType
Control10..1
BindingThe codes SHALL be taken from DocumentEntry.healthcareFacilityTypeCodeThe codes SHOULD be taken from DocumentEntry.healthcareFacilityTypeCode XDS Facility Type
Must Supporttrue
33. DocumentReference.context.practiceSetting
Control10..1
BindingThe codes SHALL be taken from DocumentEntry.practiceSettingCodeThe codes SHOULD be taken from DocumentEntry.practiceSettingCode Additional details about where the content was created (e.g. clinical specialty)
Must Supporttrue
34. DocumentReference.context.sourcePatientInfo
Control10..1
TypeReference(CHCorePatient) : {c}
Must Supporttrue
Comments

Contained Patient resource with Patient.identifier.use element set to ‘usual’.

Indicates that the data within the XDS document entry be represented as a contained resource. See Section 4.5.4.4.7

35. DocumentReference.context.related
Must Supporttrue
Comments

May be filled with URL pointers to Resources or Identifiers found in referenceIdList

May be identifiers or resources that caused the DocumentReference or referenced Document to be created.

36. DocumentReference.context.related.identifier
NoteThis is a business identifier, not a resource identifier (see discussion)
Control0..?
Must Supporttrue

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

1. DocumentReference
Definition

A reference to a document of any kind for any purpose. Provides metadata about the document so that the document can be discovered and managed. The scope of a document is any seralized object with a mime-type, so includes formal patient centric documents (CDA), cliical notes, scanned paper, and non-patient specific documents like policy text.

Control0..*
Summaryfalse
Comments

Usually, this is used for documents other than those defined by FHIR.

InvariantsDefined on this element
ch-mhd: The DocumentReference needs to conform to IHE.MHD.Comprehensive.DocumentReference (: conformsTo('https://profiles.ihe.net/ITI/MHD/StructureDefinition/IHE.MHD.Comprehensive.DocumentReference'))
dom-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. DocumentReference.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.

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

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
3. DocumentReference.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.

Control10..*
TypeExtension
Must Supporttrue
Summaryfalse
Alternate Namesextensions, user content
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.

InvariantsDefined on this element
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())
SlicingThis element introduces a set of slices on DocumentReference.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
4. DocumentReference.extension:deletionStatus
SliceNamedeletionStatus
Definition

Extension

Control0..1 This element is affected by the following invariants: ele-1
TypeExtension(ChExtDeletionStatus) (Extension Type: Coding)
Must Supporttrue
InvariantsDefined on this element
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())
5. DocumentReference.extension:originalProviderRole
SliceNameoriginalProviderRole
Definition

Extension

Control1..1 This element is affected by the following invariants: ele-1
TypeExtension(ChExtAuthorAuthorRole) (Extension Type: Coding)
Must Supporttrue
InvariantsDefined on this element
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())
6. DocumentReference.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).

Control0..*
TypeExtension
Is Modifiertrue
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
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.

InvariantsDefined on this element
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())
7. DocumentReference.masterIdentifier
Definition

An identifier - identifies some entity uniquely and unambiguously. Typically this is used for business identifiers.

Document identifier as assigned by the source of the document. This identifier is specific to this version of the document. This unique identifier may be used elsewhere to identify this version of the document.

Control10..1 This element is affected by the following invariants: ele-1
TypeIdentifier(OidIdentifier)
Must Supporttrue
Requirements

The structure and format of this Id shall be consistent with the specification corresponding to the formatCode attribute. (e.g. for a DICOM standard document a 64-character numeric UID, for an HL7 CDA format a serialization of the CDA Document Id extension and root in the form "oid^extension", where OID is a 64 digits max, and the Id is a 16 UTF-8 char max. If the OID is coded without the extension then the '^' character shall not be included.).

Comments

See ITI TF-2: Z.9.1.1 Identifier and CDA root plus extension.

CDA Document Id extension and root.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
8. DocumentReference.identifier
Definition

Other identifiers associated with the document, including version independent identifiers.

NoteThis is a business identifier, not a resource identifier (see discussion)
Control0..*
TypeIdentifier
Must Supporttrue
Summarytrue
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
9. DocumentReference.status
Definition

The status of this document reference.

Control1..1
BindingThe codes SHALL be taken from DocumentReferenceStatus

The status of the document reference.

Typecode
Is Modifiertrue
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Comments

approved -> status=current, deprecated -> status=superseded

This is the status of the DocumentReference object, which might be independent from the docStatus element.

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

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
10. DocumentReference.docStatus
Definition

The status of the underlying document.

Control0..01
BindingThe codes SHALL be taken from CompositionStatus

Status of the underlying document.

Typecode
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summarytrue
Comments

These HL7 FHIR elements are not used in XDS, therefore would not be present. Document Consumers should be robust to these elements holding values.

The document that is pointed to might be in various lifecycle states.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
11. DocumentReference.type
Definition

Specifies the particular kind of document referenced (e.g. History and Physical, Discharge Summary, Progress Note). This usually equates to the purpose of making the document referenced.

Control10..1
BindingThe codes SHALL be taken from DocumentEntry.typeCodeThe codes SHOULD be taken from DocumentTypeValueSet
TypeCodeableConcept
Must Supporttrue
Summarytrue
Comments

Key metadata element describing the document that describes he exact type of document. Helps humans to assess whether the document is of interest when viewing a list of documents.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
12. DocumentReference.category
Definition

A categorization for the type of document referenced - helps for indexing and searching. This may be implied by or derived from the code specified in the DocumentReference.type.

Control10..1*
BindingThe codes SHALL be taken from DocumentEntry.classCodeFor example codes, see DocumentClassValueSet
TypeCodeableConcept
Must Supporttrue
Summarytrue
Alternate Namesclaxs
Comments

Key metadata element describing the the category or classification of the document. This is a broader perspective that groups similar documents based on how they would be used. This is a primary key used in searching.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
13. DocumentReference.subject
Definition

Who or what the document is about. The document can be about a person, (patient or healthcare practitioner), a device (e.g. a machine) or even a group of subjects (such as a document about a herd of farm animals, or a set of patients that share a common exposure).

Control10..1
TypeReference(CHCorePatient|Patient|Practitioner|Group|Device) : {r}
Must Supporttrue
Summarytrue
Comments

Not a contained resource. URL Points to an existing Patient Resource representing the XDS Affinity Domain Patient.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
14. DocumentReference.date
Definition

When the document reference was created.

Control10..1
Typeinstant
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Alternate Namesindexed
Comments

Referencing/indexing time is used for tracking, organizing versions and searching.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
15. DocumentReference.author
Definition

Identifies who is responsible for adding the information to the document.

Control0..*
TypeReference(Practitioner|PractitionerRole|Organization|Device|Patient|RelatedPerson) : {c}
Must Supporttrue
Summarytrue
Comments

Contained resource.

Not necessarily who did the actual data entry (i.e. typist) or who was the source (informant).

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
16. DocumentReference.authenticator
Definition

Which person or organization authenticates that this document is valid.

Control0..1
TypeReference(Practitioner|PractitionerRole|Organization) : {c}
Summaryfalse
Comments

Represents a participant within the author institution who has legally authenticated or attested the document. Legal authentication implies that a document has been signed manually or electronically by the legal Authenticator.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
17. DocumentReference.custodian
Definition

Identifies the organization or group who is responsible for ongoing maintenance of and access to the document.

Control0..01
TypeReference(CHCoreOrganization|Organization)
Summaryfalse
Comments

Identifies the logical organization (software system, vendor, or department) to go to find the current version, where to report issues, etc. This is different from the physical location (URL, disk drive, or server) of the document, which is the technical location of the document, which host may be delegated to the management of some other organization.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
18. DocumentReference.relatesTo
Definition

Relationships that this document has with other document references that already exist.

Control0..*
TypeBackboneElement
Must Supporttrue
Summarytrue
Comments

See ITI TF-2c: 3.65.4.1.2.3

This element is labeled as a modifier because documents that append to other documents are incomplete on their own.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
19. DocumentReference.relatesTo.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).

Control0..*
TypeExtension
Is Modifiertrue
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
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.

InvariantsDefined on this element
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())
20. DocumentReference.relatesTo.code
Definition

The type of relationship that this document has with anther document.

Control1..1
BindingThe codes SHALL be taken from DocumentRelationshipType

The type of relationship between documents.

Typecode
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summarytrue
Comments

If this document appends another document, then the document cannot be fully understood without also accessing the referenced document.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
21. DocumentReference.relatesTo.target
Definition

The target document of this relationship.

Control1..1
TypeReference(CHCoreDocumentReference|DocumentReference)
Summarytrue
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
22. DocumentReference.description
Definition

Human-readable description of the source document.

Control0..1
Typestring
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Requirements

Helps humans to assess whether the document is of interest.

Comments

What the document is about, a terse summary of the document.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
23. DocumentReference.securityLabel
Definition

A set of Security-Tag codes specifying the level of privacy/security of the Document. Note that DocumentReference.meta.security contains the security labels of the "reference" to the document, while DocumentReference.securityLabel contains a snapshot of the security labels on the document the reference refers to.

Control10..*
BindingThe codes SHALL be taken from DocumentEntry.confidentialityCodeThe codes SHALL be taken from All Security Labels; other codes may be used where these codes are not suitable
TypeCodeableConcept
Must Supporttrue
Summarytrue
Requirements

Use of the Health Care Privacy/Security Classification (HCS) system of security-tag use is recommended.

Comments

Note: This is NOT the DocumentReference.meta, as that holds the meta tags for the DocumentReference itself.

The confidentiality codes can carry multiple vocabulary items. HL7 has developed an understanding of security and privacy tags that might be desirable in a Document Sharing environment, called HL7 Healthcare Privacy and Security Classification System (HCS). The following specification is recommended but not mandated, as the vocabulary bindings are an administrative domain responsibility. The use of this method is up to the policy domain such as the XDS Affinity Domain or other Trust Domain where all parties including sender and recipients are trusted to appropriately tag and enforce.

In the HL7 Healthcare Privacy and Security Classification (HCS) there are code systems specific to Confidentiality, Sensitivity, Integrity, and Handling Caveats. Some values would come from a local vocabulary as they are related to workflow roles and special projects.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
24. DocumentReference.content
Definition

The document and format referenced. There may be multiple content element repetitions, each with a different format.

Control1..1*
TypeBackboneElement
Summarytrue
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
25. DocumentReference.content.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).

Control0..*
TypeExtension
Is Modifiertrue
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
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.

InvariantsDefined on this element
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. DocumentReference.content.attachment
Definition

The document or URL of the document along with critical metadata to prove content has integrity.

Control1..1
TypeAttachment
Must Supporttrue
Summarytrue
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
27. DocumentReference.content.attachment.contentType
Definition

Identifies the type of the data in the attachment and allows a method to be chosen to interpret or render the data. Includes mime type parameters such as charset where appropriate.

Control10..1
BindingThe codes SHALL be taken from DocumentEntry.mimeTypeThe codes SHALL be taken from Mime Types
Typecode
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Requirements

Processors of the data need to be able to know how to interpret the data.

Example
General:text/plain; charset=UTF-8, image/png
InvariantsDefined on this element
ch-docref-1: The codes from the following ValueSet are 'preferred': http://fhir.ch/ig/ch-epr-term/ValueSet/DocumentEntry.mimeType (: exists())
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
28. DocumentReference.content.attachment.language
Definition

The human language of the content. The value can be any valid value according to BCP 47.

Control10..1
BindingThe codes SHALL be taken from DocumentEntry.languageCodeThe codes SHOULD be taken from CommonLanguages
Typecode
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Requirements

Users need to be able to choose between the languages in a set of attachments.

Example
General:en-AU
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
29. DocumentReference.content.attachment.data
Definition

The actual data of the attachment - a sequence of bytes, base64 encoded.

Control0..01
Typebase64Binary
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summaryfalse
Requirements

The data needs to able to be transmitted inline.

Comments

These HL7 FHIR elements are not used in XDS, therefore would not be present. Document Consumers should be robust to these elements holding values.

The base64-encoded data SHALL be expressed in the same character set as the base resource XML or JSON.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
30. DocumentReference.content.attachment.url
Definition

A location where the data can be accessed.

Control10..1
Typeurl
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Requirements

The data needs to be transmitted by reference.

Comments

If both data and url are provided, the url SHALL point to the same content as the data contains. Urls may be relative references or may reference transient locations such as a wrapping envelope using cid: though this has ramifications for using signatures. Relative URLs are interpreted relative to the service url, like a resource reference, rather than relative to the resource itself. If a URL is provided, it SHALL resolve to actual data.

Example
General:http://www.acme.com/logo-small.png
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
31. DocumentReference.content.attachment.size
Definition

The number of bytes of data that make up this attachment (before base64 encoding, if that is done).

Control0..1
TypeunsignedInt
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Requirements

Representing the size allows applications to determine whether they should fetch the content automatically in advance, or refuse to fetch it at all.

Comments

The number of bytes is redundant if the data is provided as a base64binary, but is useful if the data is provided as a url reference.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
32. DocumentReference.content.attachment.hash
Definition

The calculated hash of the data using SHA-1. Represented using base64.

Control0..1
Typebase64Binary
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Requirements

Included so that applications can verify that the contents of a location have not changed due to technical failures (e.g., storage rot, transport glitch, incorrect version).

Comments

The hash is calculated on the data prior to base64 encoding, if the data is based64 encoded. The hash is not intended to support digital signatures. Where protection against malicious threats a digital signature should be considered, see Provenance.signature for mechanism to protect a resource with a digital signature.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
33. DocumentReference.content.attachment.title
Definition

A label or set of text to display in place of the data.

Control0..1
Typestring
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Obligations
Obligations
??
Summarytrue
Requirements

Applications need a label to display to a human user in place of the actual data if the data cannot be rendered or perceived by the viewer.

Example
General:Official Corporate Logo
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
34. DocumentReference.content.attachment.creation
Definition

The date that the attachment was first created.

Control10..1
TypedateTime
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Requirements

This is often tracked as an integrity issue for use of the attachment.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
35. DocumentReference.content.format
Definition

An identifier of the document encoding, structure, and template that the document conforms to beyond the base format indicated in the mimeType.

Control10..1
BindingThe codes SHALL be taken from DocumentEntry.formatCodeThe codes SHOULD be taken from DocumentReferenceFormatCodeSet

Document Format Codes.

TypeCoding
Must Supporttrue
Summarytrue
Comments

Note that while IHE mostly issues URNs for format types, not all documents can be identified by a URI.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
36. DocumentReference.context
Definition

The clinical context in which the document was prepared.

Control10..1
TypeBackboneElement
Summarytrue
Comments

These values are primarily added to help with searching for interesting/relevant documents.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
37. DocumentReference.context.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).

Control0..*
TypeExtension
Is Modifiertrue
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
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.

InvariantsDefined on this element
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())
38. DocumentReference.context.period
Definition

The time period over which the service that is described by the document was provided.

Control0..1
TypePeriod
Must Supporttrue
Summarytrue
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
39. DocumentReference.context.facilityType
Definition

The kind of facility where the patient was seen.

Control10..1
BindingThe codes SHALL be taken from DocumentEntry.healthcareFacilityTypeCodeFor example codes, see FacilityTypeCodeValueSet

XDS Facility Type.

TypeCodeableConcept
Must Supporttrue
Summaryfalse
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
40. DocumentReference.context.practiceSetting
Definition

This property may convey specifics about the practice setting where the content was created, often reflecting the clinical specialty.

Control10..1
BindingThe codes SHALL be taken from DocumentEntry.practiceSettingCodeFor example codes, see PracticeSettingCodeValueSet

Additional details about where the content was created (e.g. clinical specialty).

TypeCodeableConcept
Must Supporttrue
Summaryfalse
Requirements

This is an important piece of metadata that providers often rely upon to quickly sort and/or filter out to find specific content.

Comments

This element should be based on a coarse classification system for the class of specialty practice. Recommend the use of the classification system for Practice Setting, such as that described by the Subject Matter Domain in LOINC.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
41. DocumentReference.context.sourcePatientInfo
Definition

The Patient Information as known when the document was published. May be a reference to a version specific, or contained.

Control10..1
TypeReference(CHCorePatient|Patient) : {c}
Must Supporttrue
Summaryfalse
Comments

Contained Patient resource with Patient.identifier.use element set to ‘usual’.

Indicates that the data within the XDS document entry be represented as a contained resource. See Section 4.5.4.4.7

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
42. DocumentReference.context.related
Definition

Related identifiers or resources associated with the DocumentReference.

Control0..*
TypeReference(Resource)
Must Supporttrue
Summaryfalse
Comments

May be filled with URL pointers to Resources or Identifiers found in referenceIdList

May be identifiers or resources that caused the DocumentReference or referenced Document to be created.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
43. DocumentReference.context.related.identifier
Definition

An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference.

NoteThis is a business identifier, not a resource identifier (see discussion)
Control0..1
TypeIdentifier
Must Supporttrue
Summarytrue
Comments

When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy.

When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference

Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it.

Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any).

InvariantsDefined on this element
ele-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.

1. DocumentReference
Definition

A reference to a document of any kind for any purpose. Provides metadata about the document so that the document can be discovered and managed. The scope of a document is any seralized object with a mime-type, so includes formal patient centric documents (CDA), cliical notes, scanned paper, and non-patient specific documents like policy text.

Control0..*
Summaryfalse
Comments

Usually, this is used for documents other than those defined by FHIR.

2. DocumentReference.id
Definition

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

Control0..1
Typeid
Summarytrue
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.

3. DocumentReference.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.

Control0..1
TypeMeta
Summarytrue
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
4. DocumentReference.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.

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

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
5. DocumentReference.language
Definition

The base language in which the resource is written.

Control0..1
BindingThe codes SHOULD be taken from CommonLanguages A human language
Additional BindingsPurpose
AllLanguagesMax Binding
Typecode
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summaryfalse
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).

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
6. DocumentReference.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.

Control0..1
TypeNarrative
Summaryfalse
Alternate Namesnarrative, html, xhtml, display
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.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
7. DocumentReference.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.

Control0..*
TypeResource
Summaryfalse
Alternate Namesinline resources, anonymous resources, contained 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.

8. DocumentReference.extension
Definition

An Extension

Control1..*
TypeExtension
Must Supporttrue
Summaryfalse
InvariantsDefined on this element
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())
SlicingThis element introduces a set of slices on DocumentReference.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
9. DocumentReference.extension:deletionStatus
SliceNamedeletionStatus
Definition

Extension

Control0..1 This element is affected by the following invariants: ele-1
TypeExtension(ChExtDeletionStatus) (Extension Type: Coding)
Must Supporttrue
InvariantsDefined on this element
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())
10. DocumentReference.extension:originalProviderRole
SliceNameoriginalProviderRole
Definition

Extension

Control1..1 This element is affected by the following invariants: ele-1
TypeExtension(ChExtAuthorAuthorRole) (Extension Type: Coding)
Must Supporttrue
InvariantsDefined on this element
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())
11. DocumentReference.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).

Control0..*
TypeExtension
Is Modifiertrue
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
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.

InvariantsDefined on this element
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())
12. DocumentReference.masterIdentifier
Definition

An identifier - identifies some entity uniquely and unambiguously. Typically this is used for business identifiers.

Control1..1 This element is affected by the following invariants: ele-1
TypeIdentifier(OidIdentifier)
Must Supporttrue
Requirements

The structure and format of this Id shall be consistent with the specification corresponding to the formatCode attribute. (e.g. for a DICOM standard document a 64-character numeric UID, for an HL7 CDA format a serialization of the CDA Document Id extension and root in the form "oid^extension", where OID is a 64 digits max, and the Id is a 16 UTF-8 char max. If the OID is coded without the extension then the '^' character shall not be included.).

Comments

See ITI TF-2: Z.9.1.1 Identifier and CDA root plus extension.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
13. DocumentReference.identifier
Definition

Other identifiers associated with the document, including version independent identifiers.

NoteThis is a business identifier, not a resource identifier (see discussion)
Control0..*
TypeIdentifier
Must Supporttrue
Summarytrue
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
14. DocumentReference.status
Definition

The status of this document reference.

Control1..1
BindingThe codes SHALL be taken from DocumentReferenceStatus The status of the document reference
Typecode
Is Modifiertrue
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Comments

approved -> status=current, deprecated -> status=superseded

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
15. DocumentReference.docStatus
Definition

The status of the underlying document.

Control0..0
BindingThe codes SHALL be taken from CompositionStatus Status of the underlying document
Typecode
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summarytrue
Comments

These HL7 FHIR elements are not used in XDS, therefore would not be present. Document Consumers should be robust to these elements holding values.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
16. DocumentReference.type
Definition

Specifies the particular kind of document referenced (e.g. History and Physical, Discharge Summary, Progress Note). This usually equates to the purpose of making the document referenced.

Control1..1
BindingThe codes SHALL be taken from DocumentEntry.typeCode
TypeCodeableConcept
Must Supporttrue
Summarytrue
Comments

Key metadata element describing the document that describes he exact type of document. Helps humans to assess whether the document is of interest when viewing a list of documents.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
17. DocumentReference.category
Definition

A categorization for the type of document referenced - helps for indexing and searching. This may be implied by or derived from the code specified in the DocumentReference.type.

Control1..1
BindingThe codes SHALL be taken from DocumentEntry.classCode
TypeCodeableConcept
Must Supporttrue
Summarytrue
Alternate Namesclaxs
Comments

Key metadata element describing the the category or classification of the document. This is a broader perspective that groups similar documents based on how they would be used. This is a primary key used in searching.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
18. DocumentReference.subject
Definition

Who or what the document is about. The document can be about a person, (patient or healthcare practitioner), a device (e.g. a machine) or even a group of subjects (such as a document about a herd of farm animals, or a set of patients that share a common exposure).

Control1..1
TypeReference(CHCorePatient) : {r}
Must Supporttrue
Summarytrue
Comments

Not a contained resource. URL Points to an existing Patient Resource representing the XDS Affinity Domain Patient.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
19. DocumentReference.date
Definition

When the document reference was created.

Control1..1
Typeinstant
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Alternate Namesindexed
Comments

Referencing/indexing time is used for tracking, organizing versions and searching.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
20. DocumentReference.author
Definition

Identifies who is responsible for adding the information to the document.

Control0..*
TypeReference
Must Supporttrue
Summarytrue
Comments

Contained resource.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
21. DocumentReference.authenticator
Definition

Which person or organization authenticates that this document is valid.

Control0..1
TypeReference
Summaryfalse
Comments

Represents a participant within the author institution who has legally authenticated or attested the document. Legal authentication implies that a document has been signed manually or electronically by the legal Authenticator.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
22. DocumentReference.custodian
Definition

Identifies the organization or group who is responsible for ongoing maintenance of and access to the document.

Control0..0
TypeReference(CHCoreOrganization)
Summaryfalse
Comments

Identifies the logical organization (software system, vendor, or department) to go to find the current version, where to report issues, etc. This is different from the physical location (URL, disk drive, or server) of the document, which is the technical location of the document, which host may be delegated to the management of some other organization.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
23. DocumentReference.relatesTo
Definition

Relationships that this document has with other document references that already exist.

Control0..*
TypeBackboneElement
Must Supporttrue
Summarytrue
Comments

See ITI TF-2c: 3.65.4.1.2.3

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
24. DocumentReference.relatesTo.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
Summaryfalse
25. DocumentReference.relatesTo.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.

Control0..*
TypeExtension
Summaryfalse
Alternate Namesextensions, user content
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.

InvariantsDefined on this element
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. DocumentReference.relatesTo.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).

Control0..*
TypeExtension
Is Modifiertrue
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
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.

InvariantsDefined on this element
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())
27. DocumentReference.relatesTo.code
Definition

The type of relationship that this document has with anther document.

Control1..1
BindingThe codes SHALL be taken from DocumentRelationshipType The type of relationship between documents
Typecode
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summarytrue
Comments

If this document appends another document, then the document cannot be fully understood without also accessing the referenced document.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
28. DocumentReference.relatesTo.target
Definition

The target document of this relationship.

Control1..1
TypeReference(CHCoreDocumentReference)
Summarytrue
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
29. DocumentReference.description
Definition

Human-readable description of the source document.

Control0..1
Typestring
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Requirements

Helps humans to assess whether the document is of interest.

Comments

What the document is about, a terse summary of the document.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
30. DocumentReference.securityLabel
Definition

A set of Security-Tag codes specifying the level of privacy/security of the Document. Note that DocumentReference.meta.security contains the security labels of the "reference" to the document, while DocumentReference.securityLabel contains a snapshot of the security labels on the document the reference refers to.

Control1..*
BindingThe codes SHALL be taken from DocumentEntry.confidentialityCode
TypeCodeableConcept
Must Supporttrue
Summarytrue
Requirements

Use of the Health Care Privacy/Security Classification (HCS) system of security-tag use is recommended.

Comments

Note: This is NOT the DocumentReference.meta, as that holds the meta tags for the DocumentReference itself.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
31. DocumentReference.content
Definition

The document and format referenced. There may be multiple content element repetitions, each with a different format.

Control1..1
TypeBackboneElement
Summarytrue
32. DocumentReference.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.

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
Summaryfalse
33. DocumentReference.content.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.

Control0..*
TypeExtension
Summaryfalse
Alternate Namesextensions, user content
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.

InvariantsDefined on this element
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())
34. DocumentReference.content.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).

Control0..*
TypeExtension
Is Modifiertrue
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
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.

InvariantsDefined on this element
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())
35. DocumentReference.content.attachment
Definition

The document or URL of the document along with critical metadata to prove content has integrity.

Control1..1
TypeAttachment
Must Supporttrue
Summarytrue
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
36. DocumentReference.content.attachment.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
Summaryfalse
37. DocumentReference.content.attachment.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.

Control0..*
TypeExtension
Summaryfalse
Alternate Namesextensions, user content
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.

InvariantsDefined on this element
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())
SlicingThis element introduces a set of slices on DocumentReference.content.attachment.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
38. DocumentReference.content.attachment.contentType
Definition

Identifies the type of the data in the attachment and allows a method to be chosen to interpret or render the data. Includes mime type parameters such as charset where appropriate.

Control1..1
BindingThe codes SHALL be taken from DocumentEntry.mimeType
Typecode
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Requirements

Processors of the data need to be able to know how to interpret the data.

Example
General:text/plain; charset=UTF-8, image/png
InvariantsDefined on this element
ch-docref-1: The codes from the following ValueSet are 'preferred': http://fhir.ch/ig/ch-epr-term/ValueSet/DocumentEntry.mimeType (: exists())
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
39. DocumentReference.content.attachment.language
Definition

The human language of the content. The value can be any valid value according to BCP 47.

Control1..1
BindingThe codes SHALL be taken from DocumentEntry.languageCode
Typecode
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Requirements

Users need to be able to choose between the languages in a set of attachments.

Example
General:en-AU
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
40. DocumentReference.content.attachment.data
Definition

The actual data of the attachment - a sequence of bytes, base64 encoded.

Control0..0
Typebase64Binary
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summaryfalse
Requirements

The data needs to able to be transmitted inline.

Comments

These HL7 FHIR elements are not used in XDS, therefore would not be present. Document Consumers should be robust to these elements holding values.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
41. DocumentReference.content.attachment.url
Definition

A location where the data can be accessed.

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

The data needs to be transmitted by reference.

Comments

If both data and url are provided, the url SHALL point to the same content as the data contains. Urls may be relative references or may reference transient locations such as a wrapping envelope using cid: though this has ramifications for using signatures. Relative URLs are interpreted relative to the service url, like a resource reference, rather than relative to the resource itself. If a URL is provided, it SHALL resolve to actual data.

Example
General:http://www.acme.com/logo-small.png
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
42. DocumentReference.content.attachment.size
Definition

The number of bytes of data that make up this attachment (before base64 encoding, if that is done).

Control0..1
TypeunsignedInt
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Requirements

Representing the size allows applications to determine whether they should fetch the content automatically in advance, or refuse to fetch it at all.

Comments

The number of bytes is redundant if the data is provided as a base64binary, but is useful if the data is provided as a url reference.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
43. DocumentReference.content.attachment.hash
Definition

The calculated hash of the data using SHA-1. Represented using base64.

Control0..1
Typebase64Binary
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Summarytrue
Requirements

Included so that applications can verify that the contents of a location have not changed due to technical failures (e.g., storage rot, transport glitch, incorrect version).

Comments

The hash is calculated on the data prior to base64 encoding, if the data is based64 encoded. The hash is not intended to support digital signatures. Where protection against malicious threats a digital signature should be considered, see Provenance.signature for mechanism to protect a resource with a digital signature.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
44. DocumentReference.content.attachment.title
Definition

A label or set of text to display in place of the data.

Control0..1
Typestring
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Must Supporttrue
Obligations
Obligations
??
Summarytrue
Requirements

Applications need a label to display to a human user in place of the actual data if the data cannot be rendered or perceived by the viewer.

Example
General:Official Corporate Logo
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
45. DocumentReference.content.attachment.creation
Definition

The date that the attachment was first created.

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

This is often tracked as an integrity issue for use of the attachment.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
46. DocumentReference.content.format
Definition

An identifier of the document encoding, structure, and template that the document conforms to beyond the base format indicated in the mimeType.

Control1..1
BindingThe codes SHALL be taken from DocumentEntry.formatCode Document Format Codes
TypeCoding
Must Supporttrue
Summarytrue
Comments

Note that while IHE mostly issues URNs for format types, not all documents can be identified by a URI.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
47. DocumentReference.context
Definition

The clinical context in which the document was prepared.

Control1..1
TypeBackboneElement
Summarytrue
Comments

These values are primarily added to help with searching for interesting/relevant documents.

48. DocumentReference.context.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
Summaryfalse
49. DocumentReference.context.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.

Control0..*
TypeExtension
Summaryfalse
Alternate Namesextensions, user content
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.

InvariantsDefined on this element
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())
50. DocumentReference.context.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).

Control0..*
TypeExtension
Is Modifiertrue
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
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.

InvariantsDefined on this element
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())
51. DocumentReference.context.encounter
Definition

Describes the clinical encounter or type of care that the document content is associated with.

Control0..*
TypeReference(CHCoreEncounter|EpisodeOfCare)
Summaryfalse
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
52. DocumentReference.context.event
Definition

This list of codes represents the main clinical acts, such as a colonoscopy or an appendectomy, being documented. In some cases, the event is inherent in the type Code, such as a "History and Physical Report" in which the procedure being documented is necessarily a "History and Physical" act.

Control0..*
BindingFor example codes, see v3 Code System ActCode This list of codes represents the main clinical acts being documented
TypeCodeableConcept
Summaryfalse
Comments

An event can further specialize the act inherent in the type, such as where it is simply "Procedure Report" and the procedure was a "colonoscopy". If one or more event codes are included, they shall not conflict with the values inherent in the class or type elements as such a conflict would create an ambiguous situation.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
53. DocumentReference.context.period
Definition

The time period over which the service that is described by the document was provided.

Control0..1
TypePeriod
Must Supporttrue
Summarytrue
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
54. DocumentReference.context.facilityType
Definition

The kind of facility where the patient was seen.

Control1..1
BindingThe codes SHALL be taken from DocumentEntry.healthcareFacilityTypeCode XDS Facility Type
TypeCodeableConcept
Must Supporttrue
Summaryfalse
InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
55. DocumentReference.context.practiceSetting
Definition

This property may convey specifics about the practice setting where the content was created, often reflecting the clinical specialty.

Control1..1
BindingThe codes SHALL be taken from DocumentEntry.practiceSettingCode Additional details about where the content was created (e.g. clinical specialty)
TypeCodeableConcept
Must Supporttrue
Summaryfalse
Requirements

This is an important piece of metadata that providers often rely upon to quickly sort and/or filter out to find specific content.

Comments

This element should be based on a coarse classification system for the class of specialty practice. Recommend the use of the classification system for Practice Setting, such as that described by the Subject Matter Domain in LOINC.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
56. DocumentReference.context.sourcePatientInfo
Definition

The Patient Information as known when the document was published. May be a reference to a version specific, or contained.

Control1..1
TypeReference(CHCorePatient) : {c}
Must Supporttrue
Summaryfalse
Comments

Contained Patient resource with Patient.identifier.use element set to ‘usual’.

Indicates that the data within the XDS document entry be represented as a contained resource. See Section 4.5.4.4.7

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
57. DocumentReference.context.related
Definition

Related identifiers or resources associated with the DocumentReference.

Control0..*
TypeReference(Resource)
Must Supporttrue
Summaryfalse
Comments

May be filled with URL pointers to Resources or Identifiers found in referenceIdList

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
58. DocumentReference.context.related.id
Definition

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

Control0..1
Typestring
XML RepresentationIn the XML format, this property is represented as an attribute.
Summaryfalse
59. DocumentReference.context.related.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.

Control0..*
TypeExtension
Summaryfalse
Alternate Namesextensions, user content
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.

InvariantsDefined on this element
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())
SlicingThis element introduces a set of slices on DocumentReference.context.related.extension. The slices are unordered and Open, and can be differentiated using the following discriminators:
  • value @ url
60. DocumentReference.context.related.reference
Definition

A reference to a location at which the other resource is found. The reference may be a relative reference, in which case it is relative to the service base URL, or an absolute URL that resolves to the location where the resource is found. The reference may be version specific or not. If the reference is not to a FHIR RESTful server, then it should be assumed to be version specific. Internal fragment references (start with '#') refer to contained resources.

Control0..1 This element is affected by the following invariants: ref-1
Typestring
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summarytrue
Comments

Using absolute URLs provides a stable scalable approach suitable for a cloud/web context, while using relative/logical references provides a flexible approach suitable for use when trading across closed eco-system boundaries. Absolute URLs do not need to point to a FHIR RESTful server, though this is the preferred approach. If the URL conforms to the structure "/[type]/[id]" then it should be assumed that the reference is to a FHIR RESTful server.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
61. DocumentReference.context.related.type
Definition

The expected type of the target of the reference. If both Reference.type and Reference.reference are populated and Reference.reference is a FHIR URL, both SHALL be consistent.

The type is the Canonical URL of Resource Definition that is the type this reference refers to. References are URLs that are relative to http://hl7.org/fhir/StructureDefinition/ e.g. "Patient" is a reference to http://hl7.org/fhir/StructureDefinition/Patient. Absolute URLs are only allowed for logical models (and can only be used in references in logical models, not resources).

Control0..1
BindingThe codes SHALL be taken from ResourceType; other codes may be used where these codes are not suitable Aa resource (or, for logical models, the URI of the logical model)
Typeuri
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Summarytrue
Comments

This element is used to indicate the type of the target of the reference. This may be used which ever of the other elements are populated (or not). In some cases, the type of the target may be determined by inspection of the reference (e.g. a RESTful URL) or by resolving the target of the reference; if both the type and a reference is provided, the reference SHALL resolve to a resource of the same type as that specified.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
62. DocumentReference.context.related.identifier
Definition

An identifier for the target resource. This is used when there is no way to reference the other resource directly, either because the entity it represents is not available through a FHIR server, or because there is no way for the author of the resource to convert a known identifier to an actual location. There is no requirement that a Reference.identifier point to something that is actually exposed as a FHIR instance, but it SHALL point to a business concept that would be expected to be exposed as a FHIR instance, and that instance would need to be of a FHIR resource type allowed by the reference.

NoteThis is a business identifier, not a resource identifier (see discussion)
Control0..1
TypeIdentifier
Must Supporttrue
Summarytrue
Comments

When an identifier is provided in place of a reference, any system processing the reference will only be able to resolve the identifier to a reference if it understands the business context in which the identifier is used. Sometimes this is global (e.g. a national identifier) but often it is not. For this reason, none of the useful mechanisms described for working with references (e.g. chaining, includes) are possible, nor should servers be expected to be able resolve the reference. Servers may accept an identifier based reference untouched, resolve it, and/or reject it - see CapabilityStatement.rest.resource.referencePolicy.

When both an identifier and a literal reference are provided, the literal reference is preferred. Applications processing the resource are allowed - but not required - to check that the identifier matches the literal reference

Applications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it.

Reference is intended to point to a structure that can potentially be expressed as a FHIR resource, though there is no need for it to exist as an actual FHIR resource instance - except in as much as an application wishes to actual find the target of the reference. The content referred to be the identifier must meet the logical constraints implied by any limitations on what resource types are permitted for the reference. For example, it would not be legitimate to send the identifier for a drug prescription if the type were Reference(Observation|DiagnosticReport). One of the use-cases for Reference.identifier is the situation where no FHIR representation exists (where the type is Reference (Any).

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
63. DocumentReference.context.related.display
Definition

Plain text narrative that identifies the resource in addition to the resource reference.

Control0..1
Typestring
Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
Obligations
Obligations
??
Summarytrue
Comments

This is generally not the same as the Resource.text of the referenced resource. The purpose is to identify what's being referenced, not to fully describe it.

InvariantsDefined on this element
ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))