15. The deletion of the L categories was approved by the IWG because state of art does not permit today to prove that mandated minimum sound of L categories sound will be benefit. Germany proposes to task an independent consultant to carry out an appropriate study on the need of minimum sound of L- and T-category.

16. The IWG proposes to close discussion on L category and keep statement of this first meeting for the informal document to be presented on 61th and for the working document to be presented GRB 62th if GRB members agree.