21. Referring to the discussion at the previous session of GRSG, the expert from Hungary introduced ECE/TRANS/WP.29/GRSG/2015/22 clarifying the requirements on the abrasion test machine. The experts from Germany informed GRSG about the status of work in ISO and announced that the corresponding ISO standard was in the process of being finalized and would hopefully be published by the end of the year. GRSG agreed to resume consideration of ECE/TRANS/WP.29/GRSG/2015/22 at its next session in April 2016.