Some sources report false news for comic effect. They expect the reader to be in on the joke and recognize that their stories are false. Usually satires and parodies are making fun of attitudes or beliefs in popular culture.
Satire: a form of literature that uses sarcasm or ridicule to make fun of the attitudes or opinions of a person or group of people.
Parody: a comic or satirical imitation of another piece of literature or work.
These websites are not considered fake news because they don't expect their readers to take them seriously: