Century Bro. This is payment receipt pdf that gets generated automatically when you make RPRF using credit card. If I can describe this payment receipt PDF better, it has receipt number (R34934..) printed at the top. At the center there is a table wiht following fields (Name, DOB, Client Id, Address, postal code, Area Code, Telephone No). Of all these fields, only name is pre-populated. so when you enter credit card details while making payment, you have to enter name as printed on the card, expiry date and CVV number. When you click submit, ( and if the payment is successfully accepted obviously) This name that you just entered on the payment page, is picked up and pre-populated on the payment receipt pdf that is generated for you.
I think they expect primary applicant to always make payment. In my case, I have used my spouse credit card, so his name is pre-populated in the name field (in RPRF payment receipt pdf). Hence the confusion, whether to fill in other fields (DOB, Client Id) of spouse or of the primary applicant..
I hope I am being able to explain this better now.