It is good to have the info about how and where you made the reservation in case you are ever challenged. I have made reservations with Carlson's website as well as National's using the codes and have never experienced any problems either, but there might come a day when someone is going to ask about the code, and the more info you have the better your chances of leaving the premises at the rate quoted. Now if only Vacation Outlet would update their free day coupons to 2005.