This is set up by the school to facilitate information management. For example, if a school needs to manage the educational management outline, it only needs to manage its code 708.

There is no correspondence with the major, but there is a specific correspondence with the title of the book.

It means nothing to you.

You don't need to care about its specific meaning.

You only need to remember the title, author, publisher and publication time, and you can find the corresponding books, including ordering books online or buying books in bookstores.