Each Invoice line charge (ibg-28) shall have an Invoice line charge reason (ibt-144) or an invoice line charge reason code (ibt-145).
//cac:InvoiceLine/cac:AllowanceCharge[cbc:ChargeIndicator = true()] | //cac:CreditNoteLine/cac:AllowanceCharge[cbc:ChargeIndicator = true()]exists(cbc:AllowanceChargeReason) or exists(cbc:AllowanceChargeReasonCode)