[ibr-072]-A Self-billed invoice MUST not include an AdditionalDocumentReference (ibg-24) simultaneously referring a self-billed invoice Object Identifier (ibt-018) and an Document Description (ibt-123).
ibr-072/ubl:Invoice | /cn:CreditNotenot(//cac:AdditionalDocumentReference[cbc:DocumentTypeCode = '130']/cbc:DocumentDescription)