25. The expert from USA, referring to ECE/TRANS/WP.29/2013/63, reported on the progress made on unresolved issues before its potential adoption. He informed GRRF about their testing schedule for the wet grip test validation. The expert from China referred to the Chinese Standard GB/T 4504-2009 for resolving remaining issues with the bead-unseating test. GRRF agreed that an additional meeting of the informal group on the Tyre GTR would be necessary, subject to the authorization at the November 2013 session of WP.29 to hold an additional meeting in January 2014. GRRF agreed that the informal group should refer to the existing terms of reference. GRRF preferred to postpone the vote by WP.29 and AC.1 on ECE/TRANS/WP.29/2013/63.