Hi,
In FBZP T-Code under the tab of All Compnay Codes, when you select your company code, then there is a field naming Vendors Sp G/L transactions to be paid and Customers Sp G/L transactions to be paid, by this the system will pick the documents which are there from the sp gl transactions maintained in such field while doing Payment. So purpose of F-47 is to make an down payment request so when the actual payment is done, this DP Request gets cleared. So according to me system will pick only those Documents having special G/L indicator which are mentioned in FBZP.
Regards,
Malhar.