53. The expert from the Russian Federation introduced GRSG-112-11 on a proposal endorsed by the Working Party on Noise (GRB) to adapt in R.E.3 the measuring units for vehicle masses from tonnes to kilograms. GRSG endorsed the proposal in principle. The secretariat suggested to also aligning in R.E.3 some sub-categories of vehicles, such as L_1A for powered cycles and L_1B for two-wheeled mopeds. The expert from EC volunteered to prepare a comparison document between the categories listed in EU Regulation No. 168/2013 and those in Revision 5 of R.E.3. GRSG noted general support and agreed to circulate GRSG-112-11 with an official symbol for consideration at its next session.