What was the use of the stone pillars of the crane Xiangyun in ancient times?

The Xiangyun stone pillar of the crane is a huge decorative stone pillar in front of large buildings such as ancient palaces and tombs. This kind of stone pillar can not only be used as a road sign, but also transmit information to passers-by. It appeared in the Yao and Shun era of primitive society. Huabiao is a columnar symbol of ancient palaces and tombs. It turned out to be a tall wooden pillar, like a flower, which has the function of expressing knowledge, so it is called Huabiao.