Deals with track systems with two poles or more for connecting luminaires to electrical supply, either of rated voltage of 440 V or less between poles with provision for earthing (class I) and rated current of 16 A or less per conductor, or rated SELV of 25 V or less without provision for earthing (class III) and rated current of 25 A or less per conductor. Track systems may also give mechanical support of luminaires. Covers track systems for interior use for mounting on, or flush with, or suspended from ceilings and walls, but not for environments where special conditions apply, such as on ships, vehicles, etc, and in hazardous environments, where explosions could happen.