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.
In CC, facets describe "personality" (the most specific subject), matter, energy, space, and time (PMEST). These facets are generally associated with every item in a library, and so form a reasonably universal sorting system.
As an example, the subject "research in the cure of tuberculosis of lungs by x-ray conducted in India in 1950" would be categorized as:
This is summarized in a specific call number:
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.
- z Generalia
- 1 Universe of Knowledge
- 2 Library Science
- 3 Book science
- 4 Journalism
- A Natural science
- B Mathematics
- B2 Algebra
- C Physics
- D Engineering
- E Chemistry
- F Technology
- G Biology
- H Geology
- HX Mining
- I Botany
- J Agriculture
- K Zoology
- L Medicine
- M Useful arts
- M7 Textiles [material]:[work]
- Δ Spiritual experience and mysticism [religion],[entity]:[problem]
- N Fine arts
- ND Sculpture
- NN Engraving
- NQ Painting
- NR Music
- O Literature
- P Linguistics
- Q Religion
- R Philosophy
- S Psychology
- T Education
- U Geography
- V History
- W Political science
- X Economics
- Y Sociology
- YZ Social Work
- Z Law
A common example of the colon classification is:
- "Research in the cure of the tuberculosis of lungs by x-ray conducted in India in 1950s":
- Main classification is Medicine
- Within Medicine, the Lungs are the main concern
- The property of the Lungs is that they are afflicted with Tuberculosis
- The Tuberculosis is being performed (:) on, that is the intent is to cure (Treatment)
- The matter that we are treating the Tuberculosis with are X-Rays
- And this discussion of treatment is regarding the Research phase
- This Research is performed within a geographical space (.) namely India
- During the time (') of 1950
- And translating into the codes listed for each subject and facet the classification becomes
- GOPINATH (M A). Colon classification: Its theory and practice. Library Herald . 26, 1 - 2; 1987; 1 - 3.
- Article in ISKO Encyclopedia of Knowledge Organization
- More Detail about the Colon Classification at ISKO Italia
- A brief history of the editions of Colon Classification