黑水城文獻中的元代信牌文書是與信牌一起使用的“黏連文字”原件。“黏連文字”具有一定的特徵與書式。元代信牌制度上承宋金,但又有所變化,並影響明清兩朝。元代信牌制度與其他牌符制度之間既有聯繫又有不同,元代設置該制度本爲約束與限制相關公務執行者,但實際上似乎並未達到這一目標。 The Yuan Dynasty letter sign instruments in the Blackwater City literature are the original “sticky letter” used with letter signs. “Glue text ” has certain characteristics and style. The Yuan Dynasty card system inherited Song Jin, but some changes, and affect the Ming and Qing dynasties. The Yuan Dynasty licensing system and other licensing system both the existing relationship between the different, the Yuan Dynasty set the system to constrain and limit the relevant business executives, but in fact did not seem to achieve this goal.