description: An absolute URI that is used to identify this artifact when it is referenced in a specification, model, design or an instance; also called its canonical identifier. This SHOULD be globally unique and SHOULD be a literal address at which an authoritative instance of this artifact is (or will be) published. This URL can be the target of a canonical reference. It SHALL remain the same when the artifact is stored on different servers. package_name: hl7.fhir.uv.extensions.r3 derivation: constraint name: ArtifactUrl type: Extension elements: extension: {index: 0} url: pattern: {type: Uri, value: 'http://hl7.org/fhir/StructureDefinition/artifact-url'} index: 1 value: choices: [valueUri] index: 3 valueUri: {type: uri, choiceOf: value, index: 4} package_version: 5.3.0-ballot-tc extensions: {} class: extension kind: complex-type url: http://hl7.org/fhir/StructureDefinition/artifact-url base: http://hl7.org/fhir/StructureDefinition/Extension version: 5.3.0-ballot-tc required: [valueUri, value]