The NFL franchise tag, explained

The NFL's window for teams to use the franchise tag opened Tuesday and runs through March 5.  JJ Stankevitz

Beginning Tuesday, Feb. 20 through 4 p.m. on March 5, teams are allowed to place the franchise tag on a player who is scheduled to become an unrestricted free agent when the new NFL league year begins on March 13.

That sounds simple enough, right? Unfortunately, there's a lot that's compli