What is a complete version of a book?

In order to guide students' reading, Zhang Zhidong summed up the previous experience and combined with his own understanding, and put forward three criteria for rare books: first, "enough books", that is, books are flawless and not deleted; The second is the "refined version", that is, the refined version; The third type is "old copy", that is, old manuscripts. Zhang Zhidong probably didn't mean to define rare books, but in order to guide students to read, he had to point out the maze and choose rare books, which also expressed his attitude towards what rare books are. Zhang's three definitions of "sufficient, refined and old" rare books can be summed up in two ways. One is that there is nothing wrong, and the other is that there is no essential difference with the ancient concept of "rare books".