Answered By: Kathryn Hepburn
Last Updated: Dec 01, 2022     Views: 697

Books in the UA Libraries are organized by the Library of Congress Classification system, which is a method for arranging library materials by subject matter. A Library of Congress call number is a string of letters and numbers that associates a particular book with its subject, and makes it possible to locate the exact book you're looking for on the library shelf.

In Scout, an item's call number appears right in the search results in a single-line string:

Screen grab from Scout results page for the book The Lonely City by Olivia Laing. The call number is circled.

On the book itself, you'll find the call number printed on a small sticker attached to the lower spine; sometimes, books that are too thin to fit the sticker will instead have the sticker on the lower left corner on the front.

A typical call number sticker will be formatted something like this:


Here's what those letter and numbers mean:

Call Number Component What it is? How do I read it?
1st line: N One or two letters indicating the subject class (first letter) & subclass (second letter) In alphabetical order: A, B, BF, … N, NA, NB… P, PQ, PS etc.
2nd line: 71 Subject subclass number As a whole number: 1, 2, 3, 45, 71, 100, 105, 1995, 2367 etc.
3rd line: .L24 The "Cutter number": combination of letters and numbers that represent the author’s name or the title of the work. (Some call numbers have more than one letter+number line.) Read the letter alphabetically. Then read the number as a decimal: .L105, L.24, L.375
4th line: 2016 The publication date Read it chronologically: 1982, 2001, 2016.

A call number sticker may also include an additional line at the end with a copy number (c.1, c.2 etc.) or volume number (v.1, v.2 etc.).

In our example above, the call number N71 .L24 2016 indicates that it's a book about Visual Arts (N), and more specifically, has to do with the theory, philosophy and/or the aesthetics of the visual arts (71). You likely won't ever need to memorize or remember Cutter numbers, but getting to know the subject classes and subclasses for your area of academic interest will help you not only find specific books on the shelf, but also serendipitously discover additional sources to aid in your research.


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