In our land of China with a long history, many industries have their own rules and taboos, and the more ancient and mysterious the craftsmanship is, the more so.
For example
When "asking for rice", you cannot ask about the cause of death; the coffin maker cannot make a coffin for yourself; the paper maker cannot draw eyes on paper figures; you cannot give an incomplete account of your performance... Once these rules and taboos are violated, there will be extremely terrible consequences. things happen.