An open or enclosed frame structure designed to accommodate (but does not include) electrical/electronic equipment mounted on standard width panels so that the equipment may be operated after installation without being removed. It must have panel mounting rails that provide a uniform pattern of mounting holes that will accommodate various combinations of standard width panels. It may include wires, cables, terminal boards, connectors, and the like, required for equipment operation. See also mounting base, electrical equipment; cabinet, electrical equipment; and case (2) (as modified). Excludes main distributing frame, telephone and intermediate distributing frame, telephone.