Both puns and saga posts are easy to deal with. There is a saga thread, keep that stuff in there, and have the mods post a warning in threads that are hijacked to that effect.. Puns are a little different as the are an evolving thing, and bring a bit of humour to the place, so maybe after x amount of them in a thread (maybe, as Blummers suggested, a page) have the mods post a warning that there should be no more. In both instances if people don't stop, give them a holiday to think about it. Repeat offenders longer holidays. All but the dimmest, or most obstinate posters, will learn pretty fast.