Changes made to data elements in UK CIP records when compared with corresponding CIP Revised records were analysed. A sample of 562 titles acquired between January 1980 and January 1982 by a random sample of public and academic libraries was used. The CIP Revised record on BLAISE was compared with the original CIP entry which appeared in the British National Bibliography. Items of information most likely to be amended were Dewey classification number, year of publication, form of heading and name added entries. Some 28 per cent of titles were affected by one or more possibly important changes.