26. GRSP resumed consideration of a proposal tabled by the expert from the Netherland (ECE/TRANS/WP.29/GRSP/2021/23), aimed at clarifying the requirements for the adjustment of the passenger seat back when installing the Hybrid-III 5th percentile female dummy. GRSP adopted ECE/TRANS/WP.29/GRSP/2021/23, not amended. The secretariat was requested to submit the proposal as draft Supplement 4 to the 01 series of amendment and as draft Supplement 3 to the 02 series of amendments to UN Regulation No. 137 (Frontal impact with focus on restraint systems) for consideration and vote at the June 2022 sessions of WP.29 and AC.1.