Assist the head linesman on in making illegal motion, illegal shifts, offside and encroachment calls
Assist the umpire with illegal use of the hands and holding calls
Assist the referee on false start calls
Make sure the quarterback does not cross the line of scrimmage before throwing the ball
Watch for offensive lineman going downfield too early on punts
Supervise the timing of the game
Supervise substitutions by the team on his side of the field

