just to moderate my negatives with a positive:
markkdown is a play on markup
#nup is kinda more comical than #ndown
#communiquay is more clever in that a quay is a landing point alongside a coast or riverbank, but it sounds almost the same to speak and is witty to those who have eyes for it
i could think of other better words for "communikeys" probably. ultimately you are talking about an access control list, right? and maybe "commun-" has some negative connotations related to politics that would be best avoided. so, something to do with permission and trust would be more amusing and witty. even just #comuniqes would be more funny, with its implication of official messages from an organisation, which in this case regulate who is in and who is out.
more application of poetry to your naming decisions would make them more marketable. is my main message. people respond to comedy much more than strictures and stipulations