Cataloging data is a specialized language used by libraries to correctly and consistently catalog and shelve new books. (Look at the lower half of the copyright page of almost any book on your bookshelf and you'll find CIP data). Created by a professional librarian schooled in cataloging science, this adds to your book's professional look and feel.

Note that you can't make this block up yourself. The Library of Congress has created specific language and formatting requirements for this data.