This part of ISO 11992 specifies the parameters and messages for electronically controlled braking systems, including ABS (anti-lock braking systems) and for running gear equipment (i.e. systems for steering, suspension and tyres), to ensure the interchange of digital information between road vehicles with a maximum authorized total mass greater than 3 500 kg, and their towed vehicles, including communication between towed vehicles. The objective of the data structure is to optimize the use of the interface, while preserving a sufficient reserve capacity for future expansion.