Invoice StructureDebit NoteBillingReferenceInvoice Document ReferenceUUIDcbc:UUID A universally unique identifier for this document reference. About Occurence: [1..1] Namespace: urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2 Example <cbc:UUID>b29bf297-96bc-4268-9ff2-fb6e283e4eef</cbc:UUID>IDDocumentTypeCode