文书传递和信息流通不但是当今社会的需要,也是古代王朝号令天下和国家政务运行的基本保证。唐朝的文书种类在《唐六典》中有简要概括,针对不同的应用而有对象等级和内容形式的严格区分,其中的重要性已愈来愈为研究者认识并有丰富成果,例如李锦绣和雷闻对“王言之制”的不同类别作过深入探讨,而利用敦煌吐鲁番资料进行公式文的专门研究,又有早前卢向前关于“牒”的文章和不久前雷闻关于 The transfer of documents and the circulation of information are not only the needs of today’s society, but also the basic guarantee that the ancient dynasties ordered the world and the state government to operate. The types of instruments in the Tang Dynasty are briefly summarized in the Tang and Six Dynasties. There is a strict distinction between object classes and content forms for different applications. The importance of the instruments has become more and more recognized by the researchers and has produced rich results. For example, Lei Wen made an in-depth discussion of the different categories of “Wang Yanzhi” and made use of the data of Dunhuang and Turfan to carry out specialized studies on the formulation of the formula, as well as earlier articles by Lu Xiangqian on the "