http://hl7.org/fhir/StructureDefinition/alternate-canonical|5.2.0

Used with inter-version extensions where the element being referenced by inter-version extension is of type 'canonical' and includes a reference to a resource whose canonical URL is different in the referencing version than it is in the FHIR version where the element was defined. E.g. if an R5 implementation were using inter-version extensions to support an element that referenced Bar, when in R7, the url would have been .../Foo. In this situation, the canonical element would have no value and would instead have an extension that referred to the canonical URL of the '../Bar' resource (which would technically not be supported in R7, but is appropriate in R5).

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

{
  "description": "Used with inter-version extensions where the element being referenced by inter-version extension is of type 'canonical' and includes a reference to a resource whose canonical URL is different in the referencing version than it is in the FHIR version where the element was defined.  E.g. if an R5 implementation were using inter-version extensions to support an element that referenced Bar, when in R7, the url would have been .../Foo.  In this situation, the canonical element would have no value and would instead have an extension that referred to the canonical URL of the '../Bar' resource (which would technically not be supported in R7, but is appropriate in R5).",
  "package": "hl7.fhir.uv.extensions@5.2.0",
  "date": "2014-04-27T00:00:00Z",
  "derivation": "constraint",
  "publisher": "HL7 International / FHIR Infrastructure",
  "fhirVersion": "5.0.0",
  "jurisdiction": [ {
    "coding": [ {
      "code": "001",
      "system": "http://unstats.un.org/unsd/methods/m49/m49.htm"
    } ]
  } ],
  "name": "AlternateCanonical",
  "mapping": [ {
    "uri": "http://hl7.org/v3",
    "name": "RIM Mapping",
    "identity": "rim"
  } ],
  "abstract": false,
  "type": "Extension",
  "experimental": false,
  "resourceType": "StructureDefinition",
  "fhirversion": null,
  "title": "Alternate Canonical",
  "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": "36ab3be2-f6dd-5477-afe8-62e77600def0",
  "kind": "complex-type",
  "url": "http://hl7.org/fhir/StructureDefinition/alternate-canonical",
  "identifier": [ {
    "value": "urn:oid:2.16.840.1.113883.4.642.5.1674",
    "system": "urn:ietf:rfc:3986"
  } ],
  "context": [ {
    "type": "element",
    "expression": "canonical"
  } ],
  "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"
}