ISO 22915 deals with the safety of industrial trucks, as defined in ISO 5053, relative to their stability and the verification of that stability. For the purposes of ISO 22915, industrial trucks are wheeled, self-propelled or pedestrian-propelled vehicles, excepting those running on rails. They are either operator-controlled or driverless and designed to carry, tow, push, lift, stack or tier in racks. This part of ISO 22915 specifies an additional test for verifying the stability of a truck stacking with mast tilted forward and load in the elevated position. It is applicable to the following types of truck: a) counterbalanced trucks with tiltable masts, as specified in ISO 22915–2; b) reach (retractable mast or forks) and straddle trucks with tiltable masts, as specified in ISO 22915–3; c) pallet stackers with tiltable masts, as specified in ISO 22915-4; d) bidirectional and multidirectional (retractable mast or forks) trucks with tiltable masts, as specified in ISO 22195–7; e) rough-terrain trucks with tiltable masts ; f) counterbalanced trucks fitted with articulated steering with tiltable masts .