THE “C” ON THE CARD MEANS CONCEALED (Article 144)

Commentary: The NMJL card has an X or a C in the right margin of each panel for each hand to indicate how the hand can be built.

• An “X” indicates that the hand can be built by claiming discards to make an exposure (i.e., meld, exposable; pung, kong, quint). When playing a hand that allows exposures, the player can call a discard at any time, even if it is not their turn.  
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• A “C” indicates that a hand must remain concealed (i.e., closed) until the hand is ready to win with one tile. When playing a hand that is concealed, a player is allowed to make a joker exchange on their turn.

Question from a player:  Sometimes, I hear players refer to a hand with a “c” to the right of it as a closed hand. Is it okay to say closed, or do I have to say concealed? I noticed on the back of the card it shows, concealed.

Answer from the NMJL: The hands are clearly marked “C” for concealed, “X” for exposed and the value to be paid for each hand. An exposure is three of a kind (Pung), four of a kind (Kong), five of a kind (Quint) or six of a kind (Sextet).

Source: Mah Jongg Made Easy (2020 page 12); Choosing a Hand, back of National Mah Jongg League Card.