Why do OOC reasons and IC reasons have to be separate? What rules that apply to any chat OOC can be applied to IC (i.e. courtesy, nothing too offensive, no spam, purposeful aggression, trolling, etc).
I actually dislike engaging in OOC interaction when in game, though I'll sometimes do it for the sake of being friendly and social (or for more practical reasons, such as that my squad is OOC and trying to talk as Tarquin would be, um, awkward). However, much as I'd love rules and enforcement of those rules in places like The Summit to be 100% IC, there are some rules that can only exist, and only be enforced, OOC.
For example, "No OOC." From the characters' perspective, it doesn't exist, so the rule cannot be enforced from that point of view.
That's an unsubtle example. There are other possibilities that blend IC and OOC problems, such as godmoding, breaking the fourth wall, and flagrant trolling that only has "punch" OOC (pulling in RL topics, for example. Characters get confused; players get annoyed).
Some OOC controls are necessary. Irritating, but true.