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University Library, University of Illinois at Urbana-Champaign

Library Organization and Classification Systems

This guide will help you understand the different classification systems in the library.

Dewey Decimal Classification

This classification scheme, designed by Melville Dewey in 1876, is used by many libraries on campus. Dewey divides knowledge into ten main classes with further subdivisions accompanied by decimal notation (for an extensive list of the classes and subdivisions, see our Dewey Decimal System page). This system allows for books on similar topics to be near each other on the shelves.

Anatomy of a Call Number

Q 855.1 Ec70 i:E cop2. Q is the size designation. 855.1 is the Dewey Decimal Number. Ec79 is the Cutter Number. i:E cop2 is the Work Mark and Other Information.


Size Designation relates to the physical size of the book (Q indicates a quarto while F indicates a folio).

Dewey Decimal Number indicates the class and subject matter of the book.

Cutter Number identifies who wrote the book.

Work Mark & Other Information help maintain alphabetic order in shelving and make a call number unique from other works.