The Amateur Softball Association of America, or ASA, is the national governing body of softball and outlines the rules of the game for players and umpires. Based in Oklahoma City, the association organizes a number of national tournaments and has more than 3.5 million registered players. All of these players must adhere to the specific uniform regulations that the ASA establishes.
According to rule 3, section 6 of the ASA's Softball Umpire Rulebook, every player on a team must wear a uniform identical in color and style. The sleeves or straps of a uniform's top can be adjusted with or without tie-ups as long as uniform numbers remain visible. A player or team can't be penalized if a uniform change has to be made due to blood and that uniform subsequently does not match with the rest of the team. Players can't display names or logos of any other softball association besides the ASA on their uniforms during championship play.
Ball caps are mandatory for fast-pitch male leagues and must be worn properly. Ball caps, visors and headbands are optional for female fast-pitch and all slow-pitch leagues. If one or a combination of these headwear items are worn by a team, they must all be worn properly and be of the same color. Plastic visors and handkerchiefs are not allowed.
Pants can be long, short or mixed in style, but must be alike in color. Sliding pants that are a solid color are allowed. If more than one player wears sliding pants, they must be alike in color and style. Sliding pants that are frayed, ragged or have slit legs are never allowed.
Solid-colored undershirts, including white, are allowed to be worn underneath the uniform. Though no player is required to wear an undershirt, if more than one player wears an undershirt, they must all be alike. Ragged, slit-sleeved or frayed undershirts are never allowed.
Numbers on uniforms must be of a contrasting color to the primary uniform color and at least six inches in height on the back of the uniform. The number must be visible at all times and must be an Arabic number -- 0 through 99. No two players on the same team can have the same number. This includes numbers such as 0 and 00, or 3 and 03. A player who does not have a number is not permitted to play. There is no penalty for wearing a duplicate or wrong number, but the player has to change uniforms if asked by the umpire.
Players must wear canvas, leather uppers or similar material shoes at all times during a game. Soles can have a smooth surface or soft or hard cleats. Spikes on cleats can't extend more than 3/4-inch from the sole or heel. Round metal spikes are illegal. Shoes with detachable cleats that screw onto the shoe are not allowed; however, cleats that screw into the shoe are acceptable.