It is said to have served both as a road sign and a place for passersby to leave messages, emerging as early as the time of Yao and Shun in the primitive society. Back then, people would set up a wooden pillar along major thoroughfares to identify the path and act as a marker. Later, post stations and relay stations also used it for identification purposes. It was named "Huán mù" or "Bǎo mù," later unified as "Huán mù" because the ancient character "Huán" sounds similar to "Huá," which is why it was gradually pronounced as "Huá biǎo." On this wooden pillar, passersby could carve their opinions, hence it was also known as "Bàng mù" or "Fěi bàng mù." The term "fěi bàng" in ancient times meant discussing right and wrong, akin to modern-day making suggestions, so it also served a role similar to today's "suggestion box." Historical records indicate that during Yao's time, the fěi bàng mù were cross-beamed wooden pillars.