You should experiment, but for example, adding groundunit, infantry, and armor, will make an APC symbol. GroundUnit+armor+infantry+wheeled will make a wheeled APC
Groundunit+tank+heavy will make a heavy tank.
Groundunit+armor+mortar will make a tracked self-propelled mortar.
The symbols can be added directly if desired as per the readme.
Edited by VKing, 2015-09-24 @ 11:55.