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.
element_idtypes
Identifier
Identifier.use
Identifier.type
Identifier.system
Identifier.value
Identifier.period
Identifier.assigner
Identifier
Identifier.id
Identifier.extension
Identifier.use
Identifier.type
Identifier.system
Identifier.value
Identifier.period
Identifier.assigner