description: This text is intended to act as a citation to work done elsewhere that is not part of the current stewarding process where the referenced source is in some way a basis of the current value set definition. package_name: hl7.fhir.r5.examples derivation: constraint name: sourceReference type: Extension elements: extension: {index: 0} url: pattern: {type: Uri, value: 'http://hl7.org/fhir/StructureDefinition/codesystem-sourceReference'} index: 1 value: choices: [valueUri] index: 3 valueUri: {type: uri, choiceOf: value, index: 4} package_version: 5.0.0-ballot extensions: {} class: extension kind: complex-type url: http://hl7.org/fhir/StructureDefinition/codesystem-sourceReference base: http://hl7.org/fhir/StructureDefinition/Extension version: 5.0.0-ballot required: [valueUri, value]