in team sports, the number, often referred to as the uniform number, squad number, jersey number, shirt number, sweater number, is the number worn on a player's uniform. it distinguishes each player from others wearing the same uniform. this is so that officials, scorers and spectators have something to identify each player. the number is usually shown on the back of the jersey. the player's surname is often written above or below the number. sometimes the number also displayed on the front or sleeves, or on the player's shorts or headgear.