Hold on the channel. Then hold down the function button and hit the number 5. That toggles between the TGID number and name on the 396T, it might be the same on the the 396XT.
Also I know on the 996XT you can use display mode 2 which will show the TGID and the name at the same time. So hold on the TG and hold the function key then hit 6 to change that mode.
Somebody else can pipe in and correct me if any of this is wrong.