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

Identifier Type: An identifier - identifies some entity uniquely and unambiguously. Typically this is used for business identifiers.
Base: http://hl7.org/fhir/StructureDefinition/DataType5.0.0
Type: Identifier (a.k.a: http://hl7.org/fhir/StructureDefinition/Identifier)
Type dependencies: 7
Elements