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How to Read Call Numbers: Home

Call Number Order

Call number order: Q76.K26, QA17.F75, QA17.1.C98, QA17.1.D22, TK29.M49, TK29.M5



Reading Call Numbers by Section

To read a call number, consider each section independently. BF 1556 .Z66 2010

  • BF
    Read the 1st line in alphabetical order: A, B, BF, C, D, DC...
  • 1556
    Read the 2nd line as a whole number: 1, 2, 3, 32, 100, 101, 1000, 1100, 1556, 2000, 3000...
  • Z66
    First read the 3rd line alphabetically. Then read the following number as a decimal: C51, D49,  Z616, Z66, Z8 
  • 2010
    The last line is the year, and is read in chronological order: 1989, 1992, 2000, 2010, 2016

What do call numbers mean?

Books and journals are arranged on our shelves according to the Library of Congress (LC) classification system. These call numbers uniquely identify and organize items near other material on the same or similar subjects.

Consider the call number: TK 7881.6 M29 1993

  • TK defines the class and subclass, or broad subject area. Within Class T for technology, for example, TK represents the subclass electrical engineering.
  • 7881.6, is the classification number, which defines the subject matter more finely.
  • M29, is the Cutter number and usually indicates author, though may also represent further subject subdivision or geographic area. Sometimes there are double Cutters: TK 7700 M29 A35 1990, for example.
  • 1993 is the year of publication. Not all call numbers will include the year of publication, but most recent books will. These file in chronological order and often distinguish among varying editions of a text.