If you were hoping to see a naked Michael Phelps express his admiration for the The Communist Manifesto on Twitter during the 2012 Summer Olympics, the International Olympic Committee is here to burst your bubble: The IOC says athletes will not be allowed to use the social medium to post anything political, use it for commercial purposes, or to publish X-rated photos.They’re also forbidden from acting like journalists, i.e., no going on Twitter to report you just saw Michael Phelps taking bong hits.

“First-person, diary-type” entries are all that’s allowed, the IOC said.

Athletes can post photos from Olympic venues, but no audio or video. Rules also prohibit comments about opponents, using “vulgar or obscene words or images,” and any manipulation of the five-ring Olympic symbol.