American football referees are commonly, but incorrectly, all called referees, but each official on the field has specific duties and titles: common positions include the Referee who is the lead member of the officiating team, the Umpire, the Down Judge (formerly called the Head Linesman), the Line Judge, the Back Judge, and the Side Judge. Where eight referees are used, a Center Judge is added. Because the referee is responsible for the overall supervision of the game, this role is sometimes referred to as the Head Referee.
