22. The expert of ETRTO tabled proposals for a new Supplement to the 04 series of amendments with the aim to introduce editorial corrections and the new C3 reference test tyres (ECE/TRANS/WP.29/GRBP/2024/4, ECE/TRANS/WP.29/GRBP/2024/6, GRBP-79-21). The experts from France and Japan commented on the proposals (GRBP-79-50 and GRBP-79-07). GRBP adopted the proposals in ECE/TRANS/WP.29/GRBP/2024/4 as amended by GRBP-79-50 and in ECE/TRANS/WP.29/GRBP/2024/6 as amended by GRBP-79-21, and requested the secretariat to submit them for consideration and vote at the June 2024 sessions of WP.29 and AC.1 as part of draft Supplement 2 to the 04 series of amendments to UN Regulation No. 117.

24. Similarly, the expert of ETRTO submitted proposals for a new Supplement to the 02 series of amendments which introduced editorial corrections, a temperature correction to decrease measurement uncertainties and the new C3 reference test tyres (ECE/TRANS/WP.29/GRBP/2024/5, ECE/TRANS/WP.29/GRBP/2024/7, GRBP-79-23). The expert from Japan commented on the proposals (GRBP-79-09). GRBP adopted the proposals in ECE/TRANS/WP.29/GRBP/2024/5 and in ECE/TRANS/WP.29/GRBP/2024/7 as amended by GRBP-79-23 and requested the secretariat to submit them for consideration and vote at the June 2024 sessions of WP.29 and AC.1 as draft Supplement 16 to the 02 series of amendments to UN Regulation No. 117.

25. During consideration of the above amendment proposals to various series of amendments to UN Regulation No. 117, GRBP took note of supporting material by Japan (GRBP-79-10) and by ETRTO (GRBP-79-36), as well as a summary table of all submitted documents (GRBP-79-35-Rev.2).

20. The expert from ETRTO introduced a new design of the C3 Standard Reference Test Tyres (SRTTs) that are used as reference tyres for snow grip and wet adhesion performance (GRBP-78-28-Rev.1). The expert for Japan posed a question. The Chair invited ETRTO to submit a working document for consideration at the next session.