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Books & eBooks: Library of Congress (LC) Call Numbers

This guide will help you find a specific book or books about a topic.

Understanding Library of Congress (LC) Call Numbers

Auraria Library uses the Library of Congress (LC) classification system.

What is the Library of Congress (LC) classification system? LC is an alpha-numeric system that groups books, journals and other materials by subject categories on the library shelves. 

What are call numbers? Call numbers are groups of letters and numbers that classify library items by subject. Items are arranged on bookshelves by call number. Think of it as an address for items in a library. The call number is attached to the spine of the book or a corner of the cover. 

How do I read an LC call number? Read from left to right and top to bottom.

Why is this important? It can be very useful to browse bookshelves to find books about a specific or similar topic, and to do so you will need a call number. Find a book's call number using our catalog and then locate it on the shelf. Other books next to or near this book on the shelf will be about the same or similar topics. However, broad subjects  may be divided between two or more call numbers because cataloging identifies other aspects of the general subject. For example, books on various "Cultures," may be found in several subject areas, that is, DT, E, F, GN, HD or PQ.

The image below shows an example of the the call number.

Call number in Skyline Example


The image below shows an example of a call number label on a book.

Call number on the spine of a book

Reading Library of Congress (LC) Call Numbers

How to Read LC Call Numbers [ in this example ]

  • The first line, alphabetical, identifies the subject area of the book.
  • The second line, a whole number, identifies the subject in more detail.
  • The third line puts items in author's last name order, alphabetically.
  • The last line is the year of publication










Image Credit: Honolulu Community College Library, Nadine Leong-Kurio