http://hl7.org/fhir/StructureDefinition/additionalIdentifier|5.2.0

An additional 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.

Structure JSON Dependencies FHIRSchema Other Versions Dependant (0)Elements Summary

{
  "description": "An additional 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.",
  "package": "hl7.fhir.uv.extensions.r4@5.2.0",
  "date": "2015-02-28T00:00:00Z",
  "derivation": "constraint",
  "publisher": "HL7 International / FHIR Infrastructure",
  "fhirVersion": "4.0.1",
  "jurisdiction": [ {
    "coding": [ {
      "code": "001",
      "system": "http://unstats.un.org/unsd/methods/m49/m49.htm"
    } ]
  } ],
  "name": "AdditionalIdentifier",
  "mapping": [ {
    "uri": "http://hl7.org/v3",
    "name": "RIM Mapping",
    "identity": "rim"
  } ],
  "abstract": false,
  "type": "Extension",
  "experimental": false,
  "resourceType": "StructureDefinition",
  "fhirversion": null,
  "title": "additional identifier",
  "versionAlgorithmCoding": null,
  "extension": [ {
    "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-wg",
    "valueCode": "fhir"
  }, {
    "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm",
    "valueInteger": 2
  }, {
    "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status",
    "valueCode": "trial-use"
  }, {
    "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-type-characteristics",
    "valueCode": "can-bind"
  } ],
  "status": "draft",
  "id": "c2d8df70-2c6d-5dea-9af9-f9da16ddaae6",
  "kind": "complex-type",
  "url": "http://hl7.org/fhir/StructureDefinition/additionalIdentifier",
  "identifier": [ {
    "value": "urn:oid:2.16.840.1.113883.4.642.5.1657",
    "system": "urn:ietf:rfc:3986"
  } ],
  "context": [ {
    "type": "element",
    "expression": "Reference"
  } ],
  "versionAlgorithmString": null,
  "fhir_id": null,
  "version": "5.2.0",
  "contact": [ {
    "telecom": [ {
      "value": "http://www.hl7.org/Special/committees/fiwg",
      "system": "url"
    } ]
  } ],
  "baseDefinition": "http://hl7.org/fhir/StructureDefinition/Extension"
}