 In the case of riddle jokes or one-liners the setting is implicitly understood, leaving only the dialogue and punchline to be verbalised.However, subverting these and other common guidelines can also be a source of humor—the shaggy dog story is in a class of its own as an anti-joke; although presenting as a joke, it contains a long drawn-out narrative of time, place and character, rambles through many pointless inclusions and finally fails to deliver a punchline.Jokes are a form of humour, but not all humour is a joke.