Invoice StructureDebit NoteBillingReferenceInvoice Document ReferenceDocumentTypeCodecbc:DocumentTypeCode The type of document being referenced, expressed as text. About Occurence: [1..1] Namespace: urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2 Example <cbc:DocumentTypeCode>388</cbc:DocumentTypeCode>UUIDDocumentType