Colon classification (CC) is a system of library classification developed by S. R. Ranganathan. It was the first ever faceted (or analytico-synthetic) classification. The first edition was published in 1933. Since then six more editions have been published. It is especially used in libraries in India.
Its name "colon classification" comes from the use of colons to separate facets in class numbers. However, many other classification schemes, some of which are completely unrelated, also use colons and other punctuation in various functions. They should not be confused with colon classification.
The colon classification uses 42 main classes that are combined with other letters, numbers and marks in a manner resembling the Library of Congress Classification to sort a publication.
CC uses five primary categories, or facets, to further specify the sorting of a publication. Collectively, they are called PMEST:
, Personality, the most specific or focal subject.
; Matter or property, the substance, properties or materials of the subject.
: Energy, including the processes, operations and activities.
. Space, which relates to the geographic location of the subject.
' Time, which refers to the dates or seasons of the subject.
The following are the main classes of CC, with some subclasses, the main method used to sort the subclass using the PMEST scheme and examples showing application of PMEST.
1 Universe of Knowledge
2 Library Science
3 Book science
KZ Animal Husbandry
M Useful arts
M7 Textiles [material]:[work]
Δ Spiritual experience and mysticism [religion],[entity]:[problem]
N Fine arts
W Political science