1. Warehouse system in ancient China during the Yuan and Qing Dynasties: The three warehouses in the Yuan Dynasty refer to the forbidden warehouse, the right warehouse and the left warehouse. Among them, the inner warehouse stores imperial Baoyu and exotic items from afar, the right warehouse stores gold and silver and precious silk products, and the left warehouse stores conventional clothes, silk and cloth.
2. Snooker billiards terminology: In the snooker billiards competition, "one library, two libraries and three libraries" refers to the situation that the cue ball bounces once, twice or three times when it hits the table, which is used to describe the technique or tactics of hitting the ball.
3. Concepts in the eight-character numerology: Chen, Xu, Ugliness and Unnamed in the earthly branch are called the four libraries, and one library in the eight-character is called the first library, the second library is the second library, and the third library is the third library. These four warehouses represent different five-element treasury, Chen is a reservoir, Xu is a fire warehouse, and Ugly is a treasury, not a wooden warehouse. They symbolize the treasury and are related to the accumulation of personal wealth.