Why is there no hook on the main gate of Zhengyangmen?

China has been paying attention to "taboo" since ancient times. Since Qin Shihuang, because it is called "winning politics", words with the same sound as "politics" have been avoided. So the Qin dynasty called "the first month" "the end of the month".

It is said that when an emperor went in and out of Zhengyangmen, he suddenly looked up and found that the word "A" on the door plaque of the gatehouse was ticked. He felt very unlucky in his heart. After returning to the palace, he issued an imperial edict, ordering people to rewrite the plaque of Zhengyangmen and remove the hook of the word "A" to show that it is smooth and auspicious to enter and leave Zhengyangmen, so as to show taboo.

However, the word "door" was not involved in the taboos of Ming and Qing emperors. Therefore, the removal of the word "door" on Zhengyangmen has nothing to do with taboos. The word "door" has no hook, starting with Zhu Yuanzhang, the Ming emperor.

Max Planck's On Mistakes records that Zhu Yuanzhang, the great ancestor of Ming Dynasty, ordered Zhan Xiyuan to write an inscription for Jixian Gate in imperial academy. After the inscription was written, Mao saw that the word "door" of "Jixian Gate" had a hook. He was unhappy and said, "I have to recruit talents to attract wisdom." Isn't a tick on the door blocking the way to recruit talents and attract wisdom? " So the hook was painted out. After the "door" is still the same, naturally there is no hook.