The 7th edition of Colon Classification (CC) was published in 1987. This edition introduced significant updates to S.R. Ranganathan's classification system, incorporating new subjects and refinements to the notation scheme. Earlier editions were published in 1933 (1st), 1939 (2nd), 1950 (3rd), 1952 (4th), 1957 (5th), and 1963 (6th).