How to tell whether a book is pirated?

There is a joke in the publishing industry: since I entered the publishing industry, I only read the copyright page. Because the copyright page is equivalent to a book's ID card, you can learn all the information about the book from it. If the copyright information is incomplete, irregular and inaccurate, it must be piracy. The easiest way to teach you a book is to find at least three books and put them on the copyright page together. See if it contains the same information, such as CIP data, author, editor, printing factory, printing number, printing time, ISBN, pricing and so on. If one of the books is inconsistent with the other two, it may be pirated.