description: The identifier that is used to identify this version of the artifact when it is referenced in a specification, model, design or instance. This is an arbitrary value managed by the artifact author and is not expected to be globally unique. For example, it might be a timestamp (e.g. yyyymmdd) if a managed version is not available. There is also no expectation that versions can be placed in a lexicographical sequence. package_name: hl7.fhir.uv.extensions.r4 derivation: constraint name: ArtifactVersion type: Extension elements: extension: {index: 0} url: pattern: {type: Uri, value: 'http://hl7.org/fhir/StructureDefinition/artifact-version'} index: 1 value: choices: [valueString] index: 3 valueString: {type: string, choiceOf: value, index: 4} package_version: 5.1.0 extensions: {} class: extension kind: complex-type url: http://hl7.org/fhir/StructureDefinition/artifact-version base: http://hl7.org/fhir/StructureDefinition/Extension version: 5.1.0 required: [valueString, value]