{
  "resourceType": "StructureDefinition",
  "id": "Referral-Identifier-EXT",
  "url": "http://fhir.infoway-inforoute.ca/io/CA-eReC/StructureDefinition/Referral-Identifier-EXT",
  "name": "ReferralIdentifier",
  "status": "draft",
  "description": "For requisitions this extension is used to convey the ServiceRequest.requisition identifier in the message header.",
  "fhirVersion": "4.0.1",
  "kind": "complex-type",
  "abstract": false,
  "context": [
    {
      "type": "element",
      "expression": "MessageHeader"
    }
  ],
  "type": "Extension",
  "baseDefinition": "http://hl7.org/fhir/StructureDefinition/Extension",
  "derivation": "constraint",
  "differential": {
    "element": [
      {
        "id": "Extension",
        "path": "Extension",
        "definition": "For requisitions this extension is used to convey the ServiceRequest.requisition identifier in the MessageHeader.",
        "min": 0,
        "max": "1"
      },
      {
        "id": "Extension.extension",
        "path": "Extension.extension",
        "max": "0"
      },
      {
        "id": "Extension.url",
        "path": "Extension.url",
        "fixedUri": "http://fhir.infoway-inforoute.ca/io/CA-eReC/StructureDefinition/Referral-Identifier-EXT"
      },
      {
        "id": "Extension.value[x]",
        "path": "Extension.value[x]",
        "min": 1,
        "type": [
          {
            "code": "Identifier"
          }
        ]
      }
    ]
  }
}