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Finding and Using Books from Galvin Library: 4. Book organization


Galvin Library has both fiction (such as novels) and nonfiction books. We use the Library of Congress Classification system to organize books by subject.

Reading Library of Congress call numbers


  1. Call numbers start with one or two letters. Books are arranged alphabetically on the shelf first. Single letters precede two-letter sequences that begin with the same letter. For example, all call numbers starting with Q will appear before all books starting with QA.
  2. After the letter(s), numbers appear. Read this as a whole number, as books will be organized from smallest to largest number on the shelf. For example, a book with a call number starting with "Q2" will appear before a book starting with "Q18," since 2 is less than 18.
  3. After the first set of letters/numbers, a decimal appears. Treat the letters/numbers that appear after in the same way as before the decimal (i.e., read the number as a whole number). The last 4 digits are typically the year of publication.

Example of call numbers in order:

  1. Q181.A286 2008
  2. Q310.J65 2008
  3. QA13.M374 2007

These three books would appear like this on the shelves:

Book 1:     Book 2:     Book 3:
Q                 Q                QA
181             310            13
A286           J65            M374
2008          2008          2007

Where are the fiction books? Where can I find all the books about my major?

Some of the most common questions librarians receive are "Where are all your fiction books?" and "I need books about [insert any major here], where are they?" If you've ever had these questions or wondered how the call number system works, read on.

Galvin Library uses the Library of Congress classification system.  This system arranges books according to a book's primary subject, and assigns each book a unique "call number" used to locate the book on the shelf.  So, if you'd like to browse the shelves for a topic, check the Library of Congress list of classification numbers. Just note that there might be relevant books about your topic categorized elsewhere, so search the catalog, too.

Fiction and literature are also categorized in the system, but are located in a few different places. For fiction, check these locations:

  • The Leisure Reading collection, located on the northwest shelves on the upper level. The leisure reading collection includes more contemporary titles.
  • Between call numbers PN and PZ of the upper level circulating collection. This section includes the "classics" and literary criticism.
  • Additional graphic novels are located at the circulation desk.

Subject categories for Library of Congress call numbers

The following list shows you some of the most popular sections of the Library of Congress used by IIT.  To see a more detailed list, including all the categories, click here.

B: Philosophy, Psychology, Religion

BF: Psychology

E: United States History

F: United States Local History

F536 - F550: Illinois

G: Geography, Anthropology, Recreation

GE: Environmental sciences

GF: Human ecology

H: Social Sciences

HA: Statistics

HD: Industries, Land use, Labor

HF: Commerce

HG: Finance

HQ: The family, marriage, and women

HT: Communities, classes, races

J: Political Science

JC: Political theory

JF-JQ: Public administration

L: Education

LB: Theory and practice of education

N: Fine Arts

NA: Architecture

P: Language and Literature

PN: General literature

PR: English literature

PS: American literature

PZ: Fiction and juvenile literature

Q: Science

QA: Mathematics

QA76: Computer software

QB: Astronomy

QC: Physics

QD: Chemistry

QE: Geology

QL: Zoology

QM: Human anatomy

QR: Microbiology

R: Medicine

T: Technology

TA: Engineering, Civil Engineering (General)

TD: Environmental Technology, Sanitary Engineering

TE: Highway Engineering, Roads and Pavements

TG: Bridge engineering

TH: Building construction

TJ: Mechanical engineering and machinery

TK: Electrical engineering

TK5101-TK6720: Telecommunications

TL: Motor Vehicles, Aeronautics, Astronautics

TN: Mining engineering, Metallurgy

TP: Chemical technology, Chemical engineering

Paul V. Galvin Library

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IIT Galvin Library
Paul V. Galvin Library
Illinois Institute of Technology
(312) 567-6847