If "Invoice type code" (BT-3) contains the code 384 (Corrected invoice), "PRECEDING INVOICE REFERENCE" (BG-3) should be provided at least once.
DE-R-026pxs-taxdata:TaxData/pxs-taxdata:ReportedTransaction/pxs-taxdata:ReportedDocument/pxs-taxdata:ReportedDocument[$supplierCountryIsDE and $customerCountryIsDE]((not(pxs-taxdata:DocumentTypeCode = 384) or (cac:BillingReference/cac:InvoiceDocumentReference)))