In that building a clan can choose any ONE clan that will aid him in attack of another clan's territory. only in attack not in defence.
Only one clan can be chosen and if you want to change for another clan alteration will take place only in 5 days.
moreover now tactics guild will encourage winners of 3*3 PVP clan wars if diference of the sums of levels of sides is no more that five. (it is not said but i guess winners will get TG points)
