What the hell is that all about? RP server here. It drives me absolutely insane!!! Grant it, I laugh sometimes, but for the most part it annoys the living crap outta me. I know I can just as easily turn it off, but sometimes you can learn things from /ooc. I don't mind if someone asks "Where is Fangbreaker Keep? I have been looking for two hours and can't find it?" That, is a constructive /ooc. It helps others out who may have the same question, but are too afraid to ask.
And why use /ooc as your marketplace? That is why there is an independent /auction command. If that isn't enough, join a market channel or sell from your room.
IMO, I think out of character chat on an RP server is irrelevant. The whole point of RP is (are you ready for this) TO RP!!! EQ1 had it right with learning languages. I enjoyed learning them and would constantly look for language groups. As soon as ooc reared it's ugly head, language groups became obsolete.
If you don't want to RP, don't join an RP server. And if you must use the /ooc command, be respectful of the other players in the zone. No one cares what you did with whom or what might be growing on your member.
/sigh of relief
/rant off