What is a booth review in football?

* For the first 28 minutes of each half, coaches must challenge an official's call to have it reviewed. * Coaches are allowed two challenges per game. If a call is not overturned, the challenging team loses a timeout. * No challenges will be recognized if a team has exhausted its timeouts * In the final two minutes of each half and in overtime, only the NFL replay assistant in the television booth or press box can call for a video review. There is no limit to the number of replay reviews the replay assistant can request. * A review called for by the replay assistant is not tied to timeouts for either team. * The referee will make all determinations, regardless of time of game, after reviewing videos on a sideline monitor. * A time limit of 90 seconds has been placed on all video reviews. * Replay assistants will be part of a game's officiating crew.