http://hl7.org/fhir/StructureDefinition/artifact-version|5.2.0

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.