This part of ISO 3691 gives safety requirements and the means for their verification for the following types of self-propelled industrial trucks (hereafter referred to as trucks), as defined in ISO 5053: a) industrial counterbalanced trucks; b) reach trucks with retractable mast or retractable fork arm carriage; c) straddle trucks; d) pallet-stacking trucks; e) high-lift platform trucks; f) trucks with elevating operator position up to 1 200 mm; g) side-loading trucks (one side only); h) lateral-stacking trucks (both sides), and lateral- and front-stacking trucks; i) pallet trucks;j) bidirectional and multidirectional trucks; k) tractors with a drawbar pull up to and including 20 000 N; l) rough-terrain counterbalanced trucks; m) industrial trucks powered by battery, diesel, gasoline or LPG (liquefied petroleum gas). NOTE 1 Trucks powered by CNG (compressed natural gas) are not dealt with. It is intended that CNG and other power sources be addressed in future revisions of this part of ISO 3691. For trucks with an elevating operator position of more than 1 200 mm and/or trucks designed to travel with an elevated load of more than 1 200 mm, this part of ISO 3691 is intended to be used in conjunction with ISO 3691-3. NOTE 2 ISO 3691-3 is not applicable to counterbalanced fork lift trucks or trucks intended for container handling. NOTE 3 Some low-level order pickers with an elevating operator's position up to and including 1 200 mm lift height can be equipped with an additional lifting device to lift the load to a maximum lift height of 1 800 mm