LC System
The Library of Congress system is used by most college and university libraries to organize books on the library shelves. It is an alpha-numeric system. Books are arranged in the library according to their subject. Because it would be impossible to describe the subject in words on the spine of each book, libraries use codes for these subjects. These codes are called "call numbers," and the system of call numbers is called a "classification scheme." Each item in the library has a label with letters and numbers (together called a call number) which indicates its place on the shelf. The letters indicate a subject area and the numbers which follow further subdivide the broader topic into more specific categories.
Both physical and online books are organized using the Library of Congress Classification. Knowing the classification scheme can help you when you are doing research for books in the library.
Some libraries (especially public libraries) use the Dewey Decimal classification scheme. At APU Libraries (as in many academic libraries) we use the Library of Congress Classification scheme, or LC for short. For detailed information about LC classes and subclasses, see the Library of Congress Classification Outline below.
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Tutorials
- Reading Call NumbersThis site from the Library Learning Center of the University System of Georgia provides an “anatomy” of an LC Call Number and tips on how to find books on the shelf
- Call Number & Shelving TutorialThis tutorial from Kent State University offers a quick reference for LoC classification and an animated video illustrating the rules for Call Numbers
- Shelf ReadingShelf-reading is an essential part of stacks maintenance. There are three main purposes to shelf reading:
1. Making sure each book/material is properly shelved in the correct location, and is correct in our library system; 2. Identifying any preservation issues; 3. Keep the shelves themselves in order.
Library of Congress Classification Outline
The following information is from the Library of Congress website that includes a list of the classifications by subject.
Listed below are the letters and titles of the main classes of the Library of Congress Classification. Click on any class to view an outline of its subclasses (https://www.loc.gov/catdir/cpso/lcco/).
The files below are available for downloading in PDF (the first link in each line), WordPerfect format (noted as WP version), and in Word format (noted as Word version).
- A -- GENERAL WORKS - WP version - Word version
- B -- PHILOSOPHY. PSYCHOLOGY. RELIGION - WP version - Word version
- C -- AUXILIARY SCIENCES OF HISTORY - WP version - Word version
- D -- WORLD HISTORY AND HISTORY OF EUROPE, ASIA, AFRICA, AUSTRALIA, NEW ZEALAND, ETC. - WP version - Word version
- E -- HISTORY OF THE AMERICAS - WP version - Word version
- F -- HISTORY OF THE AMERICAS - WP version - Word version
- G -- GEOGRAPHY. ANTHROPOLOGY. RECREATION - WP version - Word version
- H -- SOCIAL SCIENCES - WP version - Word version
- J -- POLITICAL SCIENCE - WP version - Word version
- K -- LAW - WP version - Word version
- L -- EDUCATION - WP version - Word version
- M -- MUSIC AND BOOKS ON MUSIC - WP version - Word version
- N -- FINE ARTS - WP version - Word version
- P -- LANGUAGE AND LITERATURE - WP version - Word version
- Q -- SCIENCE - WP version - Word version
- R -- MEDICINE - WP version - Word version
- S -- AGRICULTURE - WP version - Word version
- T -- TECHNOLOGY - WP version - Word version
- U -- MILITARY SCIENCE - WP version - Word version
- V -- NAVAL SCIENCE - WP version - Word version
- Z -- BIBLIOGRAPHY. LIBRARY SCIENCE. INFORMATION RESOURCES (GENERAL) - WP version - Word version
How to Read a Call Number
When you find a Library of Congress (LC) call number in your library search, notice that it is written a bit differently than it will appear on the book spine. In the database, it reads straight across. However, on the book spine, it will be broken down into components that make it easier to read.
- Books are arranged alphabetically. The first letter of an LC call number indicates the general class the call number falls within.
- Numbers follow the letters. The numbers define the subject of the book.
- The Cutter Number is the next set of numbers, and it further distinguishes the book. The Cutter Number indicates the author or title of the book.
- The edition of a volume is the next part of the call number. The year of publication follows the Cutter number to indicate the edition
(Image from the online library learning centern)
Here is an example from the library catalog:
(Images are from the Washington State University Library)
Library of Congress Classification System
The following short video clips will help you understand how the library of congress classification and how you can use it to locate books in the library: