An open altar at which instruction in the commandments was preached to the people, founded on the Mahāyāna-vaipulya sutras; the system began in 765 in the capital under 代宗 Daizong of the Tang dynasty and continued, with an interim under 武宗 Wuzong, till the 宣宗 Xuanzong period.

A Dictionary of Chinese Buddhist Terms, William Edward Soothill and Lewis Hodous