These Yao books are written in Han Chinese/Vietnamese nôm chữ characters. Until the beginning of the 20th century, government and scholarly documents in Vietnam were written in this classical Chinese. Unlike some ethnic minorities in Vietnam, the Yao have no written word of their own, poetry is spoken, so the Yao borrow these Han characters to transcribe and preserve their culture.

Since ancient times, according to Yao beliefs, all things have souls. The Yao believe there is a wind god, rain god, god of rice, vegetables and livestock. For each of them a specific worship ritual is performed. These rituals are also kept in the ancient books. Along with fortune telling, palm reading and calendars.

The Yao, a non Chinese minority moved most likely from the Yang Tse Basin many centuries ago to the Southern Chinese provinces of Hunan, Guizhou, Fujian, Guangdong, Guangxi and Yunnan. Possibly around the 13th century they pushed onwards to northern Vietnam then Laos and finally Thailand. Perhaps nine or ten centuries ago they became Taoists and adherence to this religion has helped them survive as a small but sophisticated society based on 12 original clans, with very strong traditions, customs and culture but no country of their own. To a large extent, they have maintained traditional Chinese social values and the Daoist religion.