Inbound EDI 850 Purchase Order - Save Detail Customer Specific Data

Hello,

I am looking to save information from the detail of the inbound EDI 850 customer purchase order that needs to be returned on the outbound 855 purchase order ack, 810 invoice, and 856 ASN. This data is not useful to our company except the customer requires it to be sent back to them.

Where is the best place to save of multiple pieces of inbound detail data? This data shouldn't be visible to packing lists, bill of ladings, etc. It is to be turned around and returned on the outbound EDI documents to the customer.

I was thinking that maybe the F4715 Detail Text lines might be an option. Does anyone know if this record loops and if so how many loops we can have per F47012 record?