Colon classification
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Colon classification (CC) is a library catalogue system developed by Shiyali Ramamrita Ranganathan. It was an early faceted (or analytico-synthetic) classification system. The first edition of colon classification was published in 1933,[1][2] followed by six more editions. It is primarily used in libraries in India.
Its name originates from its use of colons to separate facets into classes. Many other classification schemes, some of which are unrelated, also use colons and other punctuation to perform various functions. Originally, CC used only the colon as a separator, but since the second edition, CC has used four other punctuation symbols to identify each facet type.
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 thus form a reasonably universal sorting system.[3]
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:
Medicine,Lungs;Tuberculosis:Treatment;X-ray:Research.India'1950
This is summarized in a specific call number:
L,45;421:6;253:f.44'N5
Organization
[edit]The colon classification system uses 42 main classes that are combined with other letters, numbers, and marks in a manner resembling the Library of Congress Classification.
Facets
[edit]CC uses five primary categories, or facets, to specify the sorting of a publication. Collectively, they are called PMEST:
| Indicator | Facet |
|---|---|
| , | 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. |
Other symbols can be used to indicate components of facets called isolates, and to specify complex combinations or relationships between disciplines.
Classes
[edit]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
- LZ3 Pharmacology
- LZ5 Pharmacopoeia
- M Useful arts
- M7 Textiles [material]:[work]
- Δ Spiritual experience and mysticism [religion],[entity]:[problem]
- N Fine arts
- 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
Example
[edit]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":
- The main classification is Medicine;
- (Medicine)
- Within Medicine, the Lungs are the main concern;
- (Medicine,Lungs)
- The property of the Lungs is that they are afflicted with Tuberculosis;
- (Medicine,Lungs;Tuberculosis)
- The Tuberculosis is being performed (:) on, that is the intent is to cure (Treatment);
- (Medicine,Lungs;Tuberculosis:Treatment)
- The matter that we are treating the Tuberculosis with is X-Rays;
- (Medicine,Lungs;Tuberculosis:Treatment;X-ray)
- And this discussion of treatment is regarding the Research phase;
- (Medicine,Lungs;Tuberculosis:Treatment;X-ray:Research)
- This Research is performed within a geographical space (.), namely India;
- (Medicine,Lungs;Tuberculosis:Treatment;X-ray:Research.India)
- During the time (') of 1950;
- (Medicine,Lungs;Tuberculosis:Treatment;X-ray:Research.India'1950)
- And finally, translating into the codes listed for each subject and facet the classification becomes
L,45;421:6;253:f.44'N5
References
[edit]- ^ Raghavan, K. S (December 2015). "The colon classification: a few considerations on its future". Annals of Library and Information Studies. 62: 231–238.
- ^ S. R. Ranganathan (1933). Colon classification. Madras: The Madras Library Association. LCCN a33003280. OCLC 4597123. OL 180249M.
- ^ GOPINATH (M A). Colon classification: Its theory and practice. Library Herald. 26, 1–2; 1987; 1–3.
Further reading
[edit]- Colon Classification (6th Edition) by Shiyali Ramamrita Ranganathan, published by Ess Ess Publications, Delhi, India
- Chan, Lois Mai. Cataloging and Classification: An Introduction. 2nd ed. New York: McGraw-Hill, c. 1994. ISBN 0-07-010506-5.
Colon classification
View on Grokipedia:) to connect the first three facets, semicolons (;) for space, and apostrophes (') for time.[3][4] This notation allows for precise and adaptable subject representation, exemplified in class numbers like "2:51" for "Library classification," where "2" denotes Library Science and ":51" adds the energy facet for classification.[1]
Ranganathan conceived CC during his studies in London from 1924 to 1925, inspired by visits to the British Museum and other libraries, and refined it over the next few years before its debut.[2] The system organizes knowledge into 42 main classes, denoted by letters, numbers, or symbols (e.g., "2" for Library Science, "T" for Education), which are then subdivided into isolates and facets for synthesis.[3] Over its lifetime, CC evolved through seven editions, with the first three (1933, 1939, 1950) being rigidly faceted, the next three (1952, 1957, 1960) analytico-synthetic and more flexible, and the seventh (1987, posthumously published and edited with mixed reception due to inconsistencies) incorporating depth classification for specialized subjects.[1][4] Although primarily theoretical and used in fewer than 100 libraries worldwide—mostly in India, with usage declining since its peak in the mid-20th century—its influence extends to modern indexing languages like PRECIS and facet analysis in digital information retrieval.[5][3]
CC's significance lies in its foundational role in classification theory, promoting the idea of knowledge as multidimensional and dynamic, as outlined in Ranganathan's Prolegomena to Library Classification (1957).[1] It challenged Western enumerative models by emphasizing user needs and subject complexity, aligning with Ranganathan's Five Laws of Library Science, particularly the law that "the library is a growing organism."[4] Despite revisions ceasing after 1987 and no major updates as of 2025, its conceptual value endures in library science scholarship, particularly in discussions of faceted systems for digital environments.[5]