What does it do? and how do u use it? I forgot =/ I remember Mr.Cygnus enlightening me to it in a WCR audio ages ago but forgot now =/

even google wont help ya

It makes you single out a group of the same unit within a group I think.

tab to the group you use then press CTRL and make commands and only that tabbed part will use it

like if you got wyverns with kodos in 1 group (range) and you have wyverns highlighted press ctrl and make them dance over the trees without having the kodos running into them

You pick UD, start the game, select 3 acos + ghoul, right-click everything to the goldmine, press and hold ctrl and right click on a tree. GG