http://hl7.org/fhir/StructureDefinition/Base|5.0.0

{description: 'Base Type: Base definition for all types defined in FHIR type system.', derivation: null, name: Base, abstract: true, type: Base, class: complex-type, kind: complex-type, url: 'http://hl7.org/fhir/StructureDefinition/Base', version: 5.0.0}