The three types of Wikipedia [citation needed]

Burning plastic may produce toxic fumes.[citation needed]

"I have no doubts as to the veracity of this statement, however it would be nice if there was a cititation so people could click on it and learn more about the topic."

The population of Australia is 23 million.[citation needed]

"This seems plausible, but I really have no idea how true this sentence is, so if someone could provide a source for it that would be great."

The Earth is flat.[citation needed]

"The only reason why I didn't delete this outrageous and patently false assertion outright is because I was too afraid of the edit war that would follow."