19. The Chair of the informal working group on Regulation No. 55 (Mechanical Couplings) introduced ECE/TRANS/WP.29/GRRF/2013/16 as amended by GRRF-75-21, proposing minor amendments to UN Regulation No. 55. GRRF noted that the reference to an ISO standard had been updated and requested information on the content of this standard. GRRF agreed to resume consideration of this proposal at its next session on the basis of a revised document.