Hy all!
In the formcomp.dat we have following lines:
//GROUP_ANTI_AIRCRAFT,
//GROUP_ARMOURED_PERSONNEL_CARRIER,
//GROUP_FUEL_TANKER,
//GROUP_INFANTRY_FIGHTING_VEHICLE,
//GROUP_LIGHT_4X4_VEHICLE,
//GROUP_MAIN_BATTLE_TANK,
//GROUP_PRIMARY_FRONTLINE,
//GROUP_SCOUT_CAR,
//GROUP_SECONDARY_FRONTLINE,
//GROUP_SELF_PROPELLED_ARTILLERY,
//GROUP_SELF_PROPELLED_AAA,
//GROUP_SELF_PROPELLED_MLRS,
//GROUP_SELF_PROPELLED_SAM,
//GROUP_UTILITY_TRUCK,
//GROUP_INFANTRY,
But working only:
GROUP_PRIMARY_FRONTLINE
GROUP_SECONDARY_FRONTLINE
GROUP_SELF_PROPELLED_ARTILLERY
GROUP_SELF_PROPELLED_MLRS
GROUP_ANTI_AIRCRAFT
GROUP_INFANTRY.

I tried to create variety vehicle columnes (trucks,APC, etc), using the lines
GROUP_UTILITY_TRUCK
GROUP_FUEL_TANKER
GROUP_ARMOURED_PERSONNEL_CARRIER
GROUP_SCOUT_CAR
GROUP_LIGHT_4X4_VEHICLE
But game crashed.(Unrecognized tag). Somebody know how to do new vehicle columnes in the game?
Sorry for my english.

am I understand correctly - you want to make completely new groups (that doesn't present in current formcomp file), not just change content of available groups?