What are call numbers?

• The books at Lake Land College Library are organized by Call Number. Every book in the library has its own unique call number.
• A call number is like a book's address. It tells you where to find a book on the shelf.
• When you find a book you want in our catalog, it will give you the call number. You need to write down this number so you can find the book on the shelf.

Lake Land College Library uses the Library of Congress (LC) Classification System.

Because books using the LC system are classified by subject, books on the same topic will be shelved together. Once you find the call number of a book on your topic, you can browse the shelf for other books like it.

• This system uses a combination of letters and numbers.
• Each LC call number starts out with a letter (usually two letters), followed by a number, then a comibination of letters and numbers. (Example: QH 366.2 .P54 2002)
• Read the letters in alphabetical order.(A, B, BF, BE, D...Q, QA, QB, QH, etc.)
• Read the number as a whole number. (1, 2, 3, 45, 100, 101, 1000, 366, 2453, etc.)
• The third part is a combination of letters and numbers. Read the letter alphabetically and the number as a decimal (.P54 = .54, .P724 = .724, .P9 = .9)
• The last part is the year the book was published.

• LC separates the world of knowledge into 20 major categories, each represented by a letter.
  For example:
  • J = Political Science
  • L = Education
  • Q = Science
• These 20 major categories are further divided by a second letter.
  For example:
  • QA = Math
  • QC = Physics
  • QK = Botany
• These letters are further divided by numbers.
  For example:
  • QA 71 - 90 = Instruments and Machines
  • QA 150 - 272 = Algebra
  • QA 440 - 699 = Geometry, Trigonometry, Topology

For a full list of the 20 major categories, please see Lake Land's Library of Congress Classification System handout.

See the official Library of Congress Classification Outline for more details.

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This page was last updated on April 9, 2008 .