Residential protection is achieved with a variety of locks. Primary door locks, installed by the builder, include latches, deadlatches, and deadlocks. Auxiliary locks for increased security include night latches, rim deadlatches, rim deadlocks, tubular deadlocks, brace locks, and chain locks. Sliding glass door locks and window locks are also important. Commercial protection requires even greater security through the use of high-security pick resistant cylinders, guard plates, pushbutton locks, office equipment locks, filing cabinet bars, and door and window gates. Industrial protection can include panic bolts, exit alarm locks, electric release strikes, and double-bar locks. Legal problems are outlined, and the City of New York code--a model for other areas--is presented. Mortise locksets and their installation are described. A glossary of lock words is provided. A section on home security surveys includes practical considerations and information on door systems, types of windows, alarms, Operation Identification, and directions for conducting home security surveys.