Useful or not, it's up to you.
But the problem is that if one man makes the definition does not mean that it's correct or should fit all. So best is not to that. But for competition I can understand that some rules are made and anyone who will compete has to accept that or not compete.
Thats something else.
And one more thing, nothing on the web tells who is who, what they have done and so on. A guru may be a guru in his pack, but outside he is nothing else then anybody else. I have notice that earlier that folks goes mad because some don't know that a guy is a guru and because of that, untouchable But outside the tribe, forget old status..

