Understanding Call Numbers

Each reference book, circulating book, and journal title in the library has a unique call number which indicates exactly where the item is located within the collection and places it among other titles covering similar topics.

Call numbers appear in vertical order on the spines of books:


and in horizontal order in the online catalog:

Book StacksLB 2395 .C65 1991AVAILABLE

Note: If a book says Book Stacks in the Location column in the online catalog, the book may be checked out. Other location designations are also used, such as Reference, Periodicals, Rare Books, or Archives. Materials from these locations may be used in the library, but not checked out.

Where do call numbers come from?

Call numbers for our collection (as for many academic library collections in the United States) are constructed according to the Library of Congress (LC) Classification system, which assigns a combination of letters and numbers to represent subject areas, authors, and dates of publication. An overview of the LC Classification System may be viewed at Library of Congress Classification Outline.

What do call numbers mean?

  1. The first line - one, two, or sometimes three letters - represent the subject of the book.
  2. The second line - numbers - represent a smaller subdivision of the subject.
  3. The third line - a decimal point, a letter, and number(s) - often represents the author's last name.
  4. The fourth line (not always present) - a date - is the date the work was published.

How do I read a call number?

When reading call numbers, look at each line individually from top to bottom, and consider its significance to the shelf arrangement before moving on to the next line.

  1. Read the first line in alphabetical order: A, BL, C, DC, L, LA, LB, RC, SB...
  2. Read the second line as a whole number: 1, 2, 25, 40, 101, 1065, 2430...
  3. Read the letter in the third line alphabetically. Read the numbers after the letter as decimals, e.g. .C65=.65 and .C638=.638
  4. Read the dates in chronological order.

How are call numbers put in shelf order?

Look at each line of the call number*.

Call numbers
*Provided by Honolulu Community College

Last updated June 29, 2007