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.
package_name: uk.nhsdigital.r4
derivation: constraint
name: Extension-MessageHeader-messageId
type: Extension
elements:
  url:
    pattern: {type: Uri, value: 'https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-messageId'}
    index: 0
  value:
    choices: [valueIdentifier]
    index: 2
  valueIdentifier: {type: Identifier, choiceOf: value, index: 3}
package_version: 2.1.2-dev
class: extension
kind: complex-type
url: https://fhir.nhs.uk/StructureDefinition/Extension-MessageHeader-messageId
base: http://hl7.org/fhir/StructureDefinition/Extension
version: null
required: [valueIdentifier, value]