What type of cable tray should be used for cables on the wall

For a few types of installations, the National Electrical Code (NEC) specifies the cable tray type to be used: Single conductor cables and Type MV cables must be installed in ladder or ventilated trough cable trays. Cable tray systems are engineered support structures designed to route, support, and protect insulated electrical cables used for power distribution, control, instrumentation, and communication. Selecting the right cable tray is essential for safety, efficiency, and compliance with industry standards. [pdf]