China Library Classification adopts mixed numbering of letters and numbers, and basically adopts hierarchical numbering method. China Library Classification is mainly used to classify books in large libraries. In addition, in order to meet the needs of different library and information institutions and different types of literature classification, it also has several supporting versions: China Book Classification, China Library Classification (Simplified Edition) and China Library Classification Periodical Classification Table. 1984 Bibliographic Literature Publishing House published the second edition of China Library Classification and the second edition of Data Law. China Library Classification has been adopted by most library and information departments in China. Starting from 1988, the standard book number of books published in China adopts the category number of China Library Classification.