description: This extension enables the capability currently available through MSH-16 (Application Level acknowledgement) in HL7 Version 2 to declare at a message instance level whether a response is required or only upon error or success, or never. package_name: hl7.fhir.uv.extensions.r4 derivation: constraint name: MsgResponseRequest type: Extension elements: extension: {index: 0} url: pattern: {type: Uri, value: 'http://hl7.org/fhir/StructureDefinition/messageheader-response-request'} index: 1 value: choices: [valueCode] index: 3 valueCode: {type: code, choiceOf: value, index: 4} package_version: 5.3.0-ballot-tc extensions: {} class: extension kind: complex-type url: http://hl7.org/fhir/StructureDefinition/messageheader-response-request base: http://hl7.org/fhir/StructureDefinition/Extension version: 5.3.0-ballot-tc required: [valueCode, value]