Actually, I do think the last rule is the only one we need and we already have it (it's in the FAQ).
Friends are OK.
Excluding people who aren't your real-life friends isn't.
Do we really need more than that?
I really think we do.
As long as we make it clear that these aren't "additional rules" for people to find loopholes in or something like that, but rather clarifications of the simple policy on clanning (what you've just stated above), I think it's very helpful to have a little extra explanation so that people who
are intending to do something that we would see as clanning can look at it and better understand that they shouldn't do it—and, perhaps more importantly, so that people who are
not doing or intending anything of the kind can look at it and have confirmation that they are not breaking the rules. I have seen people accused of clanning before for perfectly innocuous behaviour, and I believe that this type of clarification can help a great deal in case like that.
