I always feel simplistic rules like these or like wikipedia's "don't be a dick" work well for small communities but never scale.<p>The ambiguity is really code for "follow implicit unstated behavioral community norms". When a community is small enough and everyone knows each other, a consensus can develop over what is appropriate behaviour. Yes people will push boundries, and there will be disagreements over what is good, but there is enough of a shared consensus on what being "good" means, you can just say "behave" and it sort of works.<p>The moment the community gets big and elements of it are strangers to one another, there is no shared meaning over what good behaviour is, even roughly, or for that matter shared context for which to evaluate the behavior in. Telling people to just play nice stops working.