Proposal to establish a new UN Regulation for type approval of motor vehicles and components using liquefied hydrogen fuel systems. The regulation applies to heavy-duty vehicles (categories M2, M3, N2, N3) and specifies requirements for liquefied hydrogen storage systems, pressure relief and shut-off devices, and vehicle fuel systems. Testing procedures include proof pressure verification, boil-off control, vacuum loss tolerance, and bonfire tests. Vehicle systems must prevent hydrogen accumulation in passenger compartments, limit exhaust hydrogen concentration, and include warning systems. Approval marks and periodic technical inspections are required.