{
  "resourceType": "StructureDefinition",
  "id": "7c11bace-9d43-4640-aa97-c2e7d7a13a57",
  "url": "https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-messageId",
  "name": "ExtensionMessageHeadermessageId",
  "status": "draft",
  "description": "This is a widely used term used to correlate the same request / event across logs with an arbitrary (but unique) value.\r\n\r\nThis can be implemented so that the response contains an un-changed Correlation ID \r\n\r\nIn Spine http requests this will match the value of NHSD-Correlation-ID header.",
  "fhirVersion": "4.0.1",
  "mapping": [
    {
      "identity": "rim",
      "uri": "http://hl7.org/v3",
      "name": "RIM Mapping"
    }
  ],
  "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.url",
        "path": "Extension.url",
        "fixedUri": "https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-messageId"
      },
      {
        "id": "Extension.value[x]",
        "path": "Extension.value[x]",
        "min": 1,
        "type": [
          {
            "code": "Identifier"
          }
        ]
      }
    ]
  }
}