Why are the pillars in front of Tiananmen Square called Hua Biao?

According to "Huai Nan Zi Zhu Shu Xun", as early as the Yao and Shun era, there was a practice of establishing "table wood" as the king "coachable" on the street to solicit public opinion to govern the world. To the Qin and Han Dynasties, table wood changed to refer to road signs, which was called Hua Biao.

In ancient times, huabiao was usually used as a symbol of tombs, palaces and ancestral temples. In fact, the original China watches were different from what we see now. It is a wooden pillar, which later evolved into a short crossbar or plank near the top of the wooden pillar, and was erected on the main road of traffic or in the court so that people could write advice or express knowledge. This watch column is also called cabinet watch, because it looks like a flower from a distance. In ancient times, flowers and China were interlinked, so it is also called China watch.