The part of Zi (works of masters, philosophers, and other treatises) in the Four Categories of ancient Chinese books is very complicated, and it includes all the books that cannot be classified into the other three parts. Classification of this part among Dunhuang documents is much more complicated owing to their particularity. On the basis of the classification of the Summary of the General Catalogue of the Four Categories while consulting the classification of other books of classic catalogues, the author classifies these documents into seven categories according to their actual contents: namely, works of masters, medicines, astronomy, and algorithms, horoscopy, reference books, art, and religions. Descriptive texts and explanation about the types of subgroups of each category are also provided.
