Four Bibliography compiled by Li Chong in the Eastern Jin Dynasty, "The Book of B and C was changed because of the four old books of Xun Xu" (Preface to Seven Records of Ruan Xiaoxu), which laid a four-part classification system of classics, history, scholars and collections.
After that, although Wang Jian's Seven Chapters and Ruan Xiaoxu's Seven Chapters appeared, the compilation of Jing Shi Zhi by Sui Shu in the early Tang Dynasty still took the road of quadrupling, which influenced and made quadrupling the mainstream of book classification in the future.
It was not until the Qing Dynasty that the Catalogue of Sikuquanshu was revised, which was the peak of the quartering method. The categories are more detailed than ever, and the division and combination are more reasonable. Today, it still has very important reference value for us to compile ancient books.
However, after the catalogue of Sikuquanshu, with the changes of the times, the four-part classification has also been questioned and challenged. In the Tongzhi period of Qing Dynasty, Zhang Zhidong compiled bibliographic answers for all the studious people, and thought that "series books are the most convenient for readers" and "there are subsets of classics and history, so it is difficult to change them into four, so there are differences", and a series department was set up outside the four departments, thus forming a new five-part classification.