29. GRSP noted that addendum 1 to Mutual Resolution No. 1 (Specifications for the Construction, Preparation and Certification of the 50th percentile male Biofidelic Rear Impact Dummy, anthropomorphic test Device (BioRID-II UN)) had been adopted at the November 2021 sessions of WP.29 and AC.3. GRSP recommended that experts who were developing similar addenda for the specifications of other dummies (e.g Q dummies) should use the above-mentioned addendum 1 developed by the expert from the United Kingdom as a blueprint.