《明史·志·卷五十》
牙牌的标识五种，用来检察上朝参拜：公、侯、伯为勋，驸马都尉为亲，文官为文，武官为武，教坊司为乐。
牙牌之号五，以察朝参：公、侯、伯曰勋，驸马都尉曰亲，文官曰文，武官曰武，教坊司曰乐。
The tooth token has five symbols, which are used to inspect those who come to the court: duke, marquis, and earl are awarded the emblem xun; the imperial son-in-law is awarded the emblem qin; the civil officials are awarded the emblem wen; the military officials are awarded the emblem wu; and the Jiaofangsi is awarded the emblem le.