Law 4 - Players' Equipment/Jerseys/Shin Guards/Casts/Splints/Orthopedic Braces
Equipment consists of a jersey (each with a unique number at least six inches high), shorts, shin guards, stockings, and shoes. Shin guards must be worn (properly covered with stockings) when a player is on the playing field. In a case where the visiting team and the home team have similar colored jerseys, the home team must change to a markedly different jersey color. Pinnies worn over a numbered uniform shirt are acceptable; otherwise, substitute uniform shirts must conform to requirements for numbering.
Goalkeepers must wear colors which distinguish them from other players, from each other, and from the referee. Articles that may constitute a danger to the wearer or any other player must be removed, i.e. jewelry, earrings, watches, barrettes, chains, belts, head coverings with any visor or protrusions, etc.
A goalkeeper may wear a soft billed cap or soft headgear with the approval of the referee.
Players will have shirts tucked in. Players who enter the field but fail to have proper equipment or who have duplicate jersey numbers will be sent to the touchline until the next stoppage in play (while their team plays short-handed) and may rejoin their team after being inspected by the referee.
Players with plaster casts or hard splints, even if padded, cannot play -- even with the permission of a parent, or medical approval. Players with orthopedic braces that have exposed or uncapped metal parts are also not allowed to play.