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Narrative

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Generated Narrative: StructureDefinition ext-R4B-Reference.identifier

Name	Flags	Card.	Type	Description & Constraints
Extension		0..1	Extension	R4B: identifier additional types
url		1..1	uri	"http://hl7.org/fhir/4.3/StructureDefinition/extension-Reference.identifier"
value[x]		0..1	Identifier	Logical reference, when literal reference is not known
Documentation for this format

Source1

{
  "resourceType": "StructureDefinition",
  "id": "ext-R4B-Reference.identifier",
  "text": {
    "status": "extensions",
    "div": "<!-- snip (see above) -->"
  },
  "extension": [
    {
      "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-wg",
      "valueCode": "fhir"
    },
    {
      "extension": [
        {
          "url": "packageId",
          "valueId": "hl7.fhir.uv.xver-r4b.r3"
        },
        {
          "url": "version",
          "valueString": "0.1.0"
        },
        {
          "url": "uri",
          "valueUri": "http://hl7.org/fhir/uv/xver/ImplementationGuide/hl7.fhir.uv.xver-r4b.r3"
        }
      ],
      "url": "http://hl7.org/fhir/StructureDefinition/package-source"
    },
    {
      "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm",
      "valueInteger": 0,
      "_valueInteger": {
        "extension": [
          {
            "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-conformance-derivedFrom",
            "valueUri": "http://hl7.org/fhir/uv/xver/ImplementationGuide/hl7.fhir.uv.xver-r4b.r3"
          }
        ]
      }
    },
    {
      "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status",
      "valueCode": "trial-use",
      "_valueCode": {
        "extension": [
          {
            "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-conformance-derivedFrom",
            "valueUri": "http://hl7.org/fhir/uv/xver/ImplementationGuide/hl7.fhir.uv.xver-r4b.r3"
          }
        ]
      }
    }
  ],
  "url": "http://hl7.org/fhir/4.3/StructureDefinition/extension-Reference.identifier",
  "version": "0.1.0",
  "name": "ExtensionReference_Identifier",
  "title": "R4B: identifier additional types",
  "status": "active",
  "experimental": false,
  "date": "2026-03-17T21:02:03.8104715+00:00",
  "publisher": "FHIR Infrastructure",
  "contact": [
    {
      "name": "FHIR Infrastructure",
      "telecom": [
        {
          "system": "url",
          "value": "http://www.hl7.org/Special/committees/fiwg"
        }
      ]
    }
  ],
  "description": "R4B: `Reference.identifier` additional types (Identifier) additional types from child elements (assigner, period, system, type, use, value)",
  "jurisdiction": [
    {
      "coding": [
        {
          "system": "http://unstats.un.org/unsd/methods/m49/m49.htm",
          "code": "001",
          "display": "World"
        }
      ]
    }
  ],
  "purpose": "This extension is part of the cross-version definitions generated to enable use of the\r\nelement `Reference.identifier` as defined in FHIR R4B\r\nin FHIR STU3.\r\n\r\nThe source element is defined as:\r\n`Reference.identifier` 0..1 `Identifier`\r\n\r\nAcross FHIR versions, the element set has been mapped as:\r\n*  R4B: `Reference.identifier` 0..1 `Identifier`\n*  R4: `Reference.identifier` 0..1 `Identifier`\n*  STU3: `Reference.identifier` 0..1 `Identifier`\r\n\r\nFollowing are the generation technical comments:\r\nElement `Reference.identifier` is mapped to FHIR STU3 element `Reference.identifier` as `SourceIsBroaderThanTarget`.\nThe mappings for `Reference.identifier` do not cover the following types: Identifier.\nThe mappings for `Reference.identifier` do not cover the following types based on type expansion: assigner, period, system, type, use, value.",
  "fhirVersion": "3.0.2",
  "mapping": [
    {
      "identity": "rim",
      "uri": "http://hl7.org/v3",
      "name": "RIM Mapping"
    }
  ],
  "kind": "complex-type",
  "abstract": false,
  "contextType": "datatype",
  "context": [
    "Reference.identifier"
  ],
  "type": "Extension",
  "baseDefinition": "http://hl7.org/fhir/StructureDefinition/Extension",
  "derivation": "constraint",
  "snapshot": {
    "element": [
      {
        "id": "Extension",
        "path": "Extension",
        "short": "R4B: identifier additional types",
        "definition": "R4B: `Reference.identifier` additional types (Identifier) additional types from child elements (assigner, period, system, type, use, value)",
        "comment": "Element `Reference.identifier` is mapped to FHIR STU3 element `Reference.identifier` as `SourceIsBroaderThanTarget`.\nThe mappings for `Reference.identifier` do not cover the following types: Identifier.\nThe mappings for `Reference.identifier` do not cover the following types based on type expansion: assigner, period, system, type, use, value.\nWhen 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. \n\nWhen 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\n\nApplications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it.\n\nReference 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).",
        "min": 0,
        "max": "1",
        "base": {
          "path": "Extension",
          "min": 0,
          "max": "*"
        },
        "condition": [
          "ele-1"
        ],
        "constraint": [
          {
            "key": "ele-1",
            "severity": "error",
            "human": "All FHIR elements must have a @value or children",
            "expression": "hasValue() | (children().count() > id.count())",
            "xpath": "@value|f:*|h:div",
            "source": "http://hl7.org/fhir/StructureDefinition/Element"
          },
          {
            "key": "ext-1",
            "severity": "error",
            "human": "Must have either extensions or value[x], not both",
            "expression": "extension.exists() != value.exists()",
            "xpath": "exists(f:extension)!=exists(f:*[starts-with(local-name(.), 'value')])",
            "source": "http://hl7.org/fhir/StructureDefinition/Extension"
          }
        ],
        "isModifier": false
      },
      {
        "id": "Extension.id",
        "path": "Extension.id",
        "representation": [
          "xmlAttr"
        ],
        "short": "xml:id (or equivalent in JSON)",
        "definition": "unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.",
        "min": 0,
        "max": "1",
        "base": {
          "path": "Element.id",
          "min": 0,
          "max": "1"
        },
        "type": [
          {
            "code": "string"
          }
        ],
        "mapping": [
          {
            "identity": "rim",
            "map": "n/a"
          }
        ]
      },
      {
        "id": "Extension.extension",
        "path": "Extension.extension",
        "slicing": {
          "discriminator": [
            {
              "type": "value",
              "path": "url"
            }
          ],
          "description": "Extensions are always sliced by (at least) url",
          "rules": "open"
        },
        "short": "Additional Content defined by implementations",
        "definition": "May be used to represent additional information that is not part of the basic definition of the element. In order 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.",
        "comment": "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.",
        "alias": [
          "extensions",
          "user content"
        ],
        "min": 0,
        "max": "*",
        "base": {
          "path": "Element.extension",
          "min": 0,
          "max": "*"
        },
        "type": [
          {
            "code": "Extension"
          }
        ],
        "mapping": [
          {
            "identity": "rim",
            "map": "n/a"
          }
        ]
      },
      {
        "id": "Extension.url",
        "path": "Extension.url",
        "representation": [
          "xmlAttr"
        ],
        "short": "identifies the meaning of the extension",
        "definition": "Source of the definition for the extension code - a logical name or a URL.",
        "comment": "The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.",
        "min": 1,
        "max": "1",
        "base": {
          "path": "Extension.url",
          "min": 1,
          "max": "1"
        },
        "type": [
          {
            "code": "uri"
          }
        ],
        "fixedUri": "http://hl7.org/fhir/4.3/StructureDefinition/extension-Reference.identifier",
        "mapping": [
          {
            "identity": "rim",
            "map": "N/A"
          }
        ]
      },
      {
        "id": "Extension.value[x]",
        "path": "Extension.value[x]",
        "short": "Logical reference, when literal reference is not known",
        "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.",
        "comment": "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. \n\nWhen 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\n\nApplications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it.\n\nReference 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).",
        "min": 0,
        "max": "1",
        "base": {
          "path": "Extension.value[x]",
          "min": 0,
          "max": "1"
        },
        "type": [
          {
            "code": "Identifier"
          }
        ],
        "mapping": [
          {
            "identity": "rim",
            "map": "N/A"
          }
        ]
      }
    ]
  },
  "differential": {
    "element": [
      {
        "id": "Extension",
        "path": "Extension",
        "short": "R4B: identifier additional types",
        "definition": "R4B: `Reference.identifier` additional types (Identifier) additional types from child elements (assigner, period, system, type, use, value)",
        "comment": "Element `Reference.identifier` is mapped to FHIR STU3 element `Reference.identifier` as `SourceIsBroaderThanTarget`.\nThe mappings for `Reference.identifier` do not cover the following types: Identifier.\nThe mappings for `Reference.identifier` do not cover the following types based on type expansion: assigner, period, system, type, use, value.\nWhen 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. \n\nWhen 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\n\nApplications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it.\n\nReference 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).",
        "min": 0,
        "max": "1",
        "base": {
          "path": "Extension",
          "min": 0,
          "max": "*"
        },
        "isModifier": false
      },
      {
        "id": "Extension.url",
        "path": "Extension.url",
        "min": 1,
        "max": "1",
        "base": {
          "path": "Extension.url",
          "min": 1,
          "max": "1"
        },
        "fixedUri": "http://hl7.org/fhir/4.3/StructureDefinition/extension-Reference.identifier"
      },
      {
        "id": "Extension.value[x]",
        "path": "Extension.value[x]",
        "short": "Logical reference, when literal reference is not known",
        "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.",
        "comment": "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. \n\nWhen 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\n\nApplications converting a logical reference to a literal reference may choose to leave the logical reference present, or remove it.\n\nReference 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).",
        "min": 0,
        "max": "1",
        "base": {
          "path": "Extension.value[x]",
          "min": 0,
          "max": "1"
        },
        "type": [
          {
            "code": "Identifier"
          }
        ]
      }
    ]
  }
}