Tvheadend

Hi to all, I would like to know if is possible include Channel Groups as tags into m3u file. I have tried to add the parameter "group-title" but it seems to be ignored by the import procedure.

(sample of m3u file)
#EXTM3U
#EXTINF:-1,tvg-id="" tvg-logo="Logo N/A" tvg-name="Rai 1 HD" group-title="",Rai 1 HD
http://xxxxxx:8000/live/SUUs2HKv3F/z7XJrqm0Wz125.m3u8

Thanks