I'm just wondering about how it works in the NFL. I know they are free to sign with any team they want, but are they called free agents under the rules? I ask because the teams that made it to the Conference Championships can't sign free agents unless one of their own is signed by someone else. So if they release a player and he is signed, does that allow them to sign a free agent? Likewise, are they prevented from signing released players unless one of their own released/free agents is signed first?