Players who display messages on T-shirts worn underneath their strips could face punishment under new proposals, reports BBC Sport.
The International Football Association Board (IFAB), the body which oversees the rules of the game, meets this weekend in Zurich, when the new regulation will be voted upon.
The new law has been proposed by the Football Association and would apply to domestic and international football.
The proposed text seeks to amend Law 4 of the game, which relates to political equipment:
It states: "Players must not reveal undergarments that show political, religious, personal slogans, statements or images, or advertising other than the manufacturer logo.
"A player/team of a player that reveals an undergarment that shows political, religious, personal slogans, statements or images, or advertising other than the manufacturers' logo will be sanctioned by the competition organiser or by Fifa."
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