1b99c1a6_4__Cataloging_Guides__Description
[Tag] 010 [Label] LCCN [Instructions] Check on the copyright page of the book (if it was published in the US) or the LC catalog for this number. If you can't find it, don't worry about it. [Description] 
A number assigned by the Library of Congress to uniquely identify the work.
4. Cataloging Guides
Description