The SK&F version of the CBCC chemical fragment code has been in operation since 1957. In 1964, we added another 107 code terms, taking into consideration the strengths and weaknesses of the SK&F-CBCC code and the codes used by the “Dokumentationsring.” The utility and limitations of the revised code are discussed, based on the experience gained from some 1200 structure searches since 1964. Sample searches are described. © 1969, American Chemical Society. All rights reserved.