佛祖統紀 41.20

41.20

三年。勅僧尼有事故者仰三綱。申州納符告注毀。在京者於祠部納告（唐稱符告者。與品官告身同。今時但稱度牒）。

In the third year, an imperial decree directed that when monks or nuns met with incidents [such as death or laicization], the three directors must report to the prefecture, submit the ordination certificates to be noted and cancelled, and those in the capital must submit the certificates to the Bureau of Sacrifices (in the Tang, the ordination certificate was called fugaoshen, matching the certificates of ranked officials; nowadays it is simply called dudie).