[UBL-CR-035]-A UBL invoice should not include the BillingReference ValidityPeriod
UBL-CR-035
pxs-taxdata:TaxData/pxs-taxdata:ReportedTransaction/pxs-taxdata:ReportedDocument
not(cac:BillingReference/cac:InvoiceDocumentReference/cac:ValidityPeriod)