When I want to find out Region A (U.S.) releases if they are region free, I check with the studio/ distributor and their likeliness to be region free, or I go check out these very useful websites....
www.axelmusic.com
http://regionfreemovies.com
Shame my Sony Blu Ray is not Region Free. My brother won a competition in Australia and got a Sony Blu Ray BDP-550. So if I don't want Region B Blu Rays as the classification codes are ruining the covers, I try to get those that are Region Free from the U.S.