Casting spells on another player anonymously...

[Cainehill]

Mostly, the ones that could possibly leave a province in the caster's control identify the caster - Call of the Wild, Call of the Winds, etc. If it's an "independent" attack force (Ghost Riders, Phantasmal Attack) or simply does damage (Seeking Arrow, Fires from Afar) then they don't have a clue, which can lead to some serious angst - players have a tendency to get pissed off when losing armies, temples, mages, etc, and get angry at the person they think is casting it, even though it might be someone else.