Says Founder Jonathn Huang: “There are two main rules at Uncyclopedia: 1) Be funny and not just stupid, and 2) Don’t be a dick. They’re in that order as well, so if you’re being funny and being a dick, there’s a chance your humour will stay, but overall, we strive to follow both rules as often as possible. We have articles that could be potentially offensive, but they stay as long as their comedy value outweighs their potential to be offensive. Sometimes, comedy can be heartless, but we try to err on the side of caution. We’re pretty adamant about not being cyber-bullies.”
Wikipedia returns the favor with this description of Uncylopedia.