Colon Classification (CC) is a system of
library classification developed by the Indian [S. R. Ranganathan]
?. It was the first ever faceted (or analytico-synthetic) classification. In an analytico-synthetic classification, subjects are divided into facets (aspects), and class numbers are synthesised from the classifications. Analytico-synthetic method is much more powerful than more traditional schemes such as the
Library of Congress classification or
Dewey Decimal Classification, but can result in much longer class numbers. It has been a major inspiration to classification researchers.
Its name "colon classification" comes from the use of colons to separate facets in class numbers. It is especially used in libraries in India.