http://hl7.org/fhir/StructureDefinition/composition-clinicaldocument-versionNumber|4.0.1

Version specific identifier for the composition, assigned when each version is created/updated.
typedestination
baseDefinitionhttp://hl7.org/fhir/StructureDefinition/Extension
typehttp://hl7.org/fhir/StructureDefinition/Extension
Extension.value[x].typehttp://hl7.org/fhir/StructureDefinition/string