In the game of football, an signal is when the QB, just before the start of the play, changes the called play at the line of scrimmage. Essentially, it's a immediate adjustment! The player might notice something on https://xem-bng-trc-tip-ko-nh-ci393658.nizarblog.com/42439085/what-represents-an-play-call-in-football-a-simple-explanation