If "Payment means type code" (BT-81) contains a code for direct debit (59), "DIRECT DEBIT" (BG-19) shall be provided.
DE-R-025-1(/ubl-invoice:Invoice/cac:PaymentMeans[cbc:PaymentMeansCode = 59] | /ubl-creditnote:CreditNote/cac:PaymentMeans[cbc:PaymentMeansCode = 59])[$supplierCountryIsDE and $customerCountryIsDE]cac:PaymentMandate