This session will provide an overview to the effective use of patent classifications.  The systems covered will be the International Patent Classification and its derivatives, the CPC and the FI systems.  You will encounter illustrations of usage for different types of patent information retrieval.  There are several mechanisms to enable the user to identify the classification marks which may be suitable for each subject-based search; tools for this will be discussed, relevant to each of the distinct classification systems covered.  The revision cycles will be described together with means for keeping your knowledge up-to-date.