8. The expert from GTB introduced ECE/TRANS/WP.29/GRE/2013/50 as amended by GRE-70-27 and GRE-70-35, clarifying definitions and requirements associated with the installation of “single lamps”, “lamps marked D” and “interdependent lamps”. GRE-70-20 was not discussed as the subject was covered by the two informal documents. GRE agreed to revisit this subject at its next session on the basis of a revised document, which the expert from GTB volunteered to prepare.