( d ) Informal meeting of the WLTP subgroup on the Development of the Harmonized driving Cycle ( WLTP-DHC ) , 5 June 2012 from 14.30 p.m. to 17.30 p.m. ; ( e ) Informal meeting of the GRPE working group on Retrofit Emission Control devices ( REC ) , 6 June 2012 from 9.30 a.m. to 12.30 p.m. ; ( f ) Informal meeting of the WLTP subgroup on the Development of the Test Procedure ( WLTP-DTP ) , 6 June 2012 from 9.30 a.m. to 17.30 p.m.. 83 .