description: Provides a reason why the expected value or elements in the element that is extended are missing. package_name: hl7.fhir.uv.extensions derivation: constraint name: DataAbsentReason type: Extension elements: extension: {index: 0} url: pattern: {type: Uri, value: 'http://hl7.org/fhir/StructureDefinition/data-absent-reason'} index: 1 value: choices: [valueCode] index: 3 valueCode: {type: code, choiceOf: value, index: 4} package_version: 5.1.0-snapshot1 extensions: {} class: extension kind: complex-type url: http://hl7.org/fhir/StructureDefinition/data-absent-reason base: http://hl7.org/fhir/StructureDefinition/Extension version: 5.1.0-snapshot1 required: [valueCode, value]