Have you ever seen that on the copyright page of a book?

That’s a holdover from a different era in printing. This used to be a method used to indicate the print run of the book. Since the printing plates were expensive to produce, printers simply reused the plates and lopped off the number at the far right. Therefore, if you have a book that has the following series on its copyright page

The content you are trying to access is only available to members.