Hello Llieff Welcome to the forums.
Is this necessary? Not if our clan is meant to be lax and inviting to people to chat.
Chatter is always welcome in clanchat, that's what makes it so fun to hang out there.
It's at everyone's
discretion to use it how she or he sees fit. Rules are broad enough to outline proper conduct. Trolls, spammers, and 'unfriendly' subjects get gone rather quickly.
a rule which says that posts in clan chat should be strictly warframe related.
No we shouldn't. If we started listing what's allowed an what not, we'd have to hotfix it bi-weekly, noone wants that, do we?
The clan chat is meant for Sharks to enjoy each others time and to talk, as they see fit. However, at the same time, it becomes increasingly difficult to ask for help when others are having off-topic conversations and hog the screen time. As for breaking the rules, it is pretty much up to the officers of the clan to decide when a rule has been broken. Personally, I will give some members "soft" warnings before giving them a strike, such as excessive off-topic spamming.