Does anyone know how the BILL_OF_EXCHANGE_FLAG in AR_RECEIPT_CLASSES is set?

In R12 we have created a new receipt class and the BILL_OF_EXCHANGE_FLAG is NULL in AR_RECEIPT_CLASSES. We have a value set which selects receipt classes where BILL_OF_EXCHANGE_FLAG = 'N'. This value set is failing for the new receipt class. Instead of having to amend the value set I was hoping to set the BILL_OF_EXCHANGE_FLAG to 'N' when the receipt class is created. This is a MANUAL receipt class that we have created.

Thanks for any help.