The report describes a large-scale computerized system for Selective Dissemination of Information (SDI) developed over the past five years at the U.S. Army Electronics Command to serve its technical personnel. The system, which uses as its document base the current accessions of the Defense Documentation Center, was developed in three phases: (1) an 18-month semiautomated test with 50 subscribers, (2) a fully automated system with about 500 subscribers, and (3) a proposed standard system for Army use. System descriptions include profiling techniques, keyword matching strategies, processing procedures, flow charts, and samples of inputs and outputs. System effectiveness is evaluated in terms of document ordering, relevance of citations, and the impact the system has had on the R and D program as revealed by responses to questionnaires. (Author)