Question regarding AVR

I was just wondering if this addon is allowed, I have heard mixed reviews some people/GM's on other servers consider it a "multi-hack" which it isn't really. It just lets you draw on the ground etc, to tell people which way to run, where to stand, etc. I haven't found much on the forums about it, there was one very inconclusive post that referred to something about it. I also heard you can't even use it in 3.3.5a Blizzard changed some game files the last version it was even usable in was 3.3.3 I honestly have no idea as I've never personally used it. Any information is helpful.