The Library of Congress Classification system (LCC) is the system that academic libraries generally use to classify and organize their materials. The cataloged materials are assigned a subject heading and call number, along with the title, author, etc. This allows materials to be organized and shelved in a consistent manner.
A call number is the mark on the spine of a library book or item, which is also listed in the library catalog to indicate the item’s location in the library. With the LCC system, each book has a unique call number which is a combination of letters and numbers. The call number can have anywhere between three and seven lines, which all indicate a different part of the book’s identity.
Example: PR 6068.O93 H337 1999
Don’t worry— you don’t need to know what all these numbers and letters mean! It might be useful to know the general subject and subclass of the topics you’ll be researching for your major (ex: RT=nursing, PS=American literature), but the catalog will always tell you where to go.
A subject heading is a word or phrase assigned to a book or other material by the LOC so that it can be classified and retrieved by that subject. Subject headings are usually nouns, like “schools”, “nuclear physics”, “local taxation”, etc. LOC subject headings can also be more detailed and specific by being inverted with a comma to add an adjective to the noun, or by using dashes to add subdivisions (subcategories). A book can have more than one subject heading; sometimes they have several.
United States—Armed Forces
Great Britain—History—William I, 1066–1087
Art, Chinese—To 221 B.C.
A — General works
B — Philosophy. Psychology. Religion
C — Auxiliary sciences of history
D — World history and history of Europe, Asia, Africa, Australia, New Zealand, etc.
E — History of the Americas
F — History of the Americas
G — Geography. Anthropology. Recreation
H — Social sciences
J — Political science
K — Law
L — Education
M — Music and books on music
N — Fine arts
P — Language and literature
Q — Science
R — Medicine
S — Agriculture
T — Technology
U — Military science
V — Naval science
Z — Bibliography. Library science. Information resources (general)