When was the first edition of Colon Classification was published?

Colon Classification is a system for organizing library materials developed by S.R. Ranganathan, an Indian librarian and library scientist. The first edition of Colon Classification was published in 1933. It has since undergone several revisions, with the most recent edition being published in 2005. The system is based on the principles of facet analysis, which involves organizing materials based on their subject matter using a set of hierarchical categories known as “facets.” Colon Classification is used in libraries around the world to organize and classify library materials in a systematic and consistent way.