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Library of Congress Classification System

Classification

Books are arranged in RIT Library by subject with all the books on one subject shelved together. Each subject is assigned a one or two letter code. The letters do not necessarily stand for the first letter of the subject they represent. For instance, Political Science is letter J, and Art is letter N. This system is called the Library of Congress classification system because it was first designed and used by the Library of Congress. You may already be familiar with another classification system which is also arranged by subject, the Dewey Decimal Classification. That system assigns a number from 001 to 900 for each subject and is used by most public libraries. Library of Congress, however is used in most academic libraries and uses letters and numbers to denote subjects.

Here is a brief listing of letters assigned to subjects:

A = General works	M = Music
B-BJ = Philosophy	N = Fine arts
BF = Psychology	P = Language & Literature
BL-BX = Religion	Q = Math, Science, Computer Science
C,D,E,F = History	R = Medicine
G = Geography, Anthropology, Recreation	S = Agriculture
H = Social Sciences, Business	T = Technology, Engineering
J = Political Science	U = Military Science
KF = Law of the United States	V = Naval Science
L = Education	Z = Bibliography, Printing, Publishing

To locate a topic more specific than those listed above use the 5 volume set of Library of Congress Subject Headings. This set can also be used to determine the terms used by LC to define a topic. Many synonyms for a word may be lumped under one specific "subject". You can find this set on the dictionary stand in the Reference Area. This classification outline is also available on the Library of Congress website.

Call Numbers

Each book is assigned a call number designating both its subject and its place on the shelf. This call number usually has three parts. The first part is one or two letters for the broad subject area. The second part is numbers and is a further subdivision of the general subject. The third part is a letter and number code for the author's name. Here are some examples and what they mean:

The call number appears on the spine of the book written vertically as above but can be written horizontally as well, for example: TK 2851 .H3. This is the way it appears in the entry in "Einstein". There is no need to memorize this classification scheme. You only need to write down the complete call number listed in the catalog to be able to find the book on the shelf.

Shelving

Books are shelved alphabetically by first letter of the first line of the call number, then by the second letter, if any. In our example, book 1 comes before book 2 because plain B comes before BF. Book 2 comes before book 3 because BF precedes, alphabetically, BT. Second lines are arranged as whole numbers with book 4 coming before book 5 because 541 comes before 964. The third line is a decimal so that book 5 would be shelved before book 6 because .A42 comes before .A7.

Special Collections

Additional locators can be added to the beginning of any call number. They change the location of the book in the library. Example:

REF HD 31.N2	OVER PR 650.A1
This call number now says that this book is shelved in the REFerence Section, 1st floor	This call number indicates a book in the OVERsized collection on the 4th floor

Locators indicate special categories of books that are shelved as separate collections. Within each collection they are then arranged in the regular call number order. Locators are generally abbreviated words. RIT Library uses the following:

General Collection

For the general collection you can remember this easy rule:
A through M = 4th floor             N through Z = 3rd floor

Maintained by: Linda Coppola