Proposal to update the transitional provisions of UN R13, including provisions for extensions of type approvals granted according to the antecedent requirements of the original approval. These amendments also relate to the transfer of brake-related telltale provisions to UN R121. The proposal also would clarify and align UN R13 with UN R107 on bus construction with regard to the exemption of articulated buses and coaches from the requirements for vehicle stability equipment. These proposals are based on documents GRRF/2014/7 and GRRF-76-20 as amended and reproduced in Annex II of the report of the GRRF on its 76th session.