Call for a Discard Must be Verbalized (Article ID 57)
Abstract: A player must verbalize their intention to call a discarded tile. They can say, “call,” “I want it, “I’ll take it,” or any variation thereof as long as they verbalize their intentions before picking up the discard.
Question from a player: A player discards a tile. The next player in turn wants to call that discard for exposure – does not say anything – and simply picks up the discard and makes her exposure.
Answer from the NMJL: “To claim a discard, the player must verbalize her call letting the other players know that she is claiming that discard. She may say, “call”, “take”, “I want that”, etc.”
Source: Mah Jongg Made Easy 2020 page 14 https://www.nationalmahjonggleague.org