You can always find various alphanumeric codes in each book on the page with the publisher's imprint. These are UDC, LBC, ISBN, ISSN, copyright mark and other indices. What do they mean and what are they for?
Publisher's imprint is the “passport data” of the publication that allows you to identify it in the document flow and facilitate its arrangement and library search.
These indices serve to find one particular book among a large amount of books. Furthermore, UDC and LBC are only library codes, and ISBN is also a guarantee that the book is officially published. All these codes and the copyright mark are also included in the publishing package.
The publishing package is a set of bibliographic indices that are assigned to a book. They are necessary for registration of the publication and its presentation in the catalogs of libraries, bookstores, government agencies.