The purpose of this guide is to give an up-to-date presentation of the information service offered by the documentation center at the Royal Institute of Technology (RIT) and to facilitate the utilization of the service. The guide gives a general account of the multidisciplinary computerized current awareness service (SDI) and a detailed description of the profiling system, including profile construction techniques and profile maintenance methods and routines. Included in this guide are descriptions of: the data bases included in the SDI service, processing of magnetic tapes, the construction of search profiles, comments on the profile print-out and on the list of references for the profile, evaluation and feedback methods, statistics compiled, contacts with users, subscription fees, etc. (Author/SJ)