Question: What does the “C” stand for on the card? I often hear players’ ‘say “Concealed Hand” or “Closed Hand”?

Answer: The proper term for the “C” on the card, is “concealed”.  When playing a concealed hand, a player cannot call a tile to complete an exposure of three or more identical tiles (i.e., pung, kong, or quint). However, when the hand is ready to win, a player can call a discard to declare Mah Jongg.

Resources: Mah Jongg Made Easy 2024, page 12; Choosing a Hand, back of National Mah Jongg League Card.