This part of ISO 10542 specifies design and performance requirements and recommendations, instructions and warnings for both installers and users, and product marking and labelling, for wheelchair tiedown and occupant-restraint systems (WTORS) that use a docking-type wheelchair tiedown. It specifies the universal docking interface geometry (UDIG) and a method of testing wheelchair movement. It is applicable to docking-type wheelchair tiedown devices intended for securing all types of manual and powered forward-facing wheelchairs, including scooters with three or more wheels, used by adult passengers and drivers of motor vehicles. This part of ISO 10542 is applicable primarily to complete WTORS, but a portion of this part of ISO 10542 can also be applied to components and sub-assemblies sold separately and for replacement parts.