Yellow card

[Tanya Shivari]

Yellow card in Volleyball. Used by the referee to signify a fault has been committed. If a referee holds up both the red and yellow cards, the offending player is sent off for the rest of the game.

[Vania]

in football, and some other sports, a small, yellow card that is shown to a player by the referee (= the official who is responsible for making certain the rules are followed) as a warning that the player has not obeyed a rule, and that they will be punished if it happens again: