Just a randomly chosen example (thank you google). 
It's fair enough for it to apply to TWC and .org, given the relation this community has with those two. That's effectively the same as the rules only referring to games played here. If you're dead set on having rules, that'd be a fair enough qualifier.
But why have rules at all, rather than some nice helpful guidelines which would seem much more appropriate coming from your locally friendly neighbourhood forum?

It's fair enough for it to apply to TWC and .org, given the relation this community has with those two. That's effectively the same as the rules only referring to games played here. If you're dead set on having rules, that'd be a fair enough qualifier.
But why have rules at all, rather than some nice helpful guidelines which would seem much more appropriate coming from your locally friendly neighbourhood forum?

). None of that crap, stay civilized.