MediaWiki:Captions
From MediaWiki

Unlike most Wikis, MediaWiki does not have a complete ban on humor, particularly in image captions where a description saying "a picture of Megatron" would be completely redundant.
MediaWiki is a fun community which welcomes new members' contributions with open arms. That said... if your idea of contributing is to change the existing jokes to new, funnier jokes... don't.
There are several reasons we discourage new users from editing image captions.
- Your jokes aren't funnier.
- Funny image captions are like a fun bonus you get to do when you make the page. For the people who wrote the text, or found and edited the images, this is their reward for that hard work. If you're not expanding the article, you really shouldn't be making jokes.
- If you're changing a joke, you're removing content created by a user who's contributed to this community, and replacing it with something from someone (yourself) who has not.
Removing Joke captions
You will be banned if you remove jokes simply for the sake of doing so. We have guidelines about what level of humor is and is not acceptable.
- For further information, see: Project:De-snarking

