Proposal to establish a new UN Regulation to help prevent children being left unattended in M2 and M3, class B and III vehicles designed specifically for the carriage of children. The regulation covers vehicles intended for child carriage and establishes minimum requirements for vehicle-based warning systems. These systems remind drivers or responsible persons to physically inspect the passenger compartment before leaving the vehicle. External visual warnings use direction indicator lamps; audible warnings use type-approved horns or reverse alarm devices, or must pass specified test procedures.