Two 80,000 barrels and three nine barrels are not Hu cards, and there is a straight between two 80,000 barrels and three nine barrels, which cannot form a Hu card type.
Mahjong Hu card type refers to various counting methods of mahjong cards, and different cards calculate different numbers. Conventional types of Hu cards include Big Four Happiness, Small Three Yuan, Big Three Yuan, Monochrome, Mixed Monochrome, Full Color and so on. Simply put, the mahjong Hu card type is the general name of the cards formed by playing mahjong Hu cards.