Please note that the techniques and rules of our company's mahjong cards are different from those of the American Mahjong Association. Our cards are refined based on the relevant techniques and rules that were pre-announced and discussed for the 2025 World Mahjong Championships and the World Mahjong Masters Tournament. We will update the product content according to the rules for contestants to practice that are released before each event. Therefore, the content of different batches of cards in different periods may vary.