I have an FT-991A and wondering about GM. When I press and hold GM I go into the group selection menu. Each item has a TX and RX box. Is this for setting the Group ID, example, if I set the TX to 01 and the RX to 00 will it show me everyone who is in GM in my area but only TX to those in Group 01? There is very little information out there and I am mostly learning by experimenting with other 991A users.