31. As per paragraphs 4 and 5, the experts from Austria and the Republic of Korea, on behalf of IWG, introduced ECE/TRANS/WP.29/GRSP/2023/33 and GRSP-74-23-Rev.1 amending it, to introduce a proposal of addendum to Mutual Resolution No.1 (M.R.1) submitted by the IWG to calculate Head Impact Time and concerning provisions for: (a) DPPS Generic Vehicle Models and (b) developing Human Body Model qualification corridors. GRSP adopted ECE/TRANS/WP.29/GRSP/2023/33, as amended by annex VIII of the session report and requested the secretariat to submit it as draft Amendment 4 to M.R.1 for consideration and vote at the June 2024 sessions of WP.29 and AC.3.