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Manual for Student Assistants (Manitowoc Location Only): Library of Congress Classification

This is the Manual for the Library Student Workers of the UWGB-Manitowoc Campus.

Call Numbers

Book spine with call number label

Library of Congress Call Letters

The following is a list of letters and the subject areas they represent in the Library of Congress call numbers. Each letter may be broken down further for a more specific subject matter.  For more information, go to the Library of Congress site

A     General Works (encyclopedias, dictionaries, indexes)

B     Philosophy- Religion

C     Auxiliary Sciences of History

D     History- General and Old World

E-F     History of America

G     Geography, Anthropology, Folklore

H     Social Studies

J     Political Science

K     Law

L     Education

M     Music

N     Fine Arts

P     Language and Literature

Q     Science

R     Medicine

S     Agriculture

T     Technology

U     Military Science

V     Naval Science

Z     Bibliography and Library Science



Library of Congress

Library of Congress call numbers are combinations of letters and numbers used to give each book in our stacks a unique address. Properly placed, books then follow one another in an alphabetic and numeric arrangement making them easy to find.

On a book, the call number will be displayed on the lower part of the spine near the bottom, usually printed on a white label:



How do you read Library of Congress Call Numbers?

The first line can either be a single or double letter. A single letter in the same letter grouping always comes first (example: P comes before PA). This first line determines what type of subject the book is and will be shelved with similar books. The first line is shelved in alphabetical order.



The second line is always a whole number from 1-9999. Books are arranged in numerical order after being grouped into the proper letters from line one. Example: PA 2 comes before PA 25.

1  23 2 25 3 5


The third line is always a decimal point followed by a letter and a number. It is important to remember the number is not a whole number but a decimal. When reading these numbers PA 135 .G22 would actually come after PA 135 .G213 because the number .213 is smaller than .22

135 135 135 135
.G213 .G22 .G2237 .G24


Hint: If you find it difficult to read decimals, add zeros to the shorter numbers when you are comparing call numbers (when comparing PA 135 .G2237 and PA 135 .G24, add zeros to .G24 to make it .G2400 and it becomes clear that .G2400 is larger than .G2237)

Sometimes there will be a fourth line that, like the third line, is a combination of letters and numbers. These are read like the third line of the call number. They will always be a decimal.

135 135 135 135 135
.G213 .G213 .G213 .G213 .G213
W415 W42 W4215 W4237 W43

The last line of a Library of Congress Call Number is usually a date of publication, a volume number, or copy number. Earlier editions are shelved first. Volumes are shelved in numerical order, as are copies. If a book has no additional line, shelve that book first (example: PA 135 .G22 comes before PA 135 .G22 1999).

Examples: PA135 .G22;   PA135 .G22 c.2;   PA135 .G22 1999;   PA135 .G22 1999 c.2

An important thing to remember while shelving is the phrase: “Nothing before something”