Ever since Buddhism was first introduced to China, si 寺 has been the most common term. for a monastery or convent. Other terms, however, have also been adopted, and patterns in their usage have varied in different periods. For example, Yuan 院, the second most common term after si first appeared in the Tang dynasty and its use spread with the increasing popularity of the Chan (Zen 禪) sect. In the Song, four terms were used: si, yuan, an 庵, and--less frequently--tang 堂. Whereas si and yuan were large establishments recognized by the government, an and tang were smaller in scale and lacked official recognition. Thus, they rarely appear in local gazetteers compiled during the Song. In Buddhist records, however, starting from the Northern Song, one finds many writings of monks and nuns whose residences are described as an. Based on data from Yuan and Ming gazetteers and on colophons of the Tripitaka printed in southern China, we know that number of an and tang increase in the Song and Yuan dynasties. These records reveal three important facts. First, in southern China, many private an were established by officials and wealthy individuals. Second, in addition to monks and nuns, upasaka--lay devotees--lived in them. And finally, they were centers for the activities of monks belonging to popular new sects such as the White Cloud Sect (Baiyunzong 白雲宗) and White Lotus Sect (Bailianzong 白蓮宗), These were distinguishing features of Buddhism in this period.
