Let me explain more. There are 3 upgrades to enhance 3 kinds of China Tank, BattleMaster, Gattling and Dragon. But only one of them can be applied at one time. if the BattleMaster's upgrade is applied, the others will not be available.
or something along those lines? And the upgrades would be Type = OBJECT I think for it to work correctly. And if you are wanting to take them off, just use the RemovesUpgrades line.
You means select one upgrade for one kind of unit and stop the player from using the other 2?
Well,use CommandSetUpgrade module for the war factory,build one upgrade and change the command buttons,which can make the player unable to build the other two upgrades
and for the upgrade's type,it is defined in upgrade.ini.the 2 types of upgrades are OBJECT and PLAYER