63. OICA introduced a list of supplements to UN Regulations which pose difficulties for obtaining extensions to existing type approvals as detailed in informal document WP.29-175-17.
64. WP.29 reiterated that on the issue of the immediate application of supplements, the principle was that supplements should only be used for the clarification of test procedures not changing the level of stringency of the regulation or imposing new requirements or for regulating new developments not changing the level of stringency of the regulation. Therefore, supplements become applicable for new approvals issued after their date of entry into force. As a result, the previous practice of occasionally including new requirements in supplements must be avoided.
65. However, to address the issue of several supplements which had been identified as containing new requirements, WP.29 clarified that the General Guidelines for United Nations regulatory procedures and transitional provisions in UN Regulations, as adopted by the WP.29 on 14 November 2017 apply to:
66. WP. 29 invited the respective GRs to immediately start working on the necessary amendments to the UN Regulations listed in the informal document WP.29-175-17.