The Model Building Codes and the International Building Code (IBC) 20002 require a smoke control system in a covered mall building occupancy that contains an atrium. A restaurant in this type of mall represents a case of mixed occupancy. The general mall occupancy areas are Mercantile Group M (retail) and Assembly Group A-2 (restaurant). Each restaurant space is required, therefore, to have a dedicated smoke control system. Contrast this to the retail areas that can be zoned with one exhaust fan serving a zone.