Form-versus-content humour is a type of humour in which the medium (loosely interpreted) in which a statement is made contributes to making the statement humourous. Usually this is by the means of having some contradiction between the medium and the message; for example, by presenting a message in a form that inherently defeats the ostensible purpose of the message, or in a form that is fundamentally incapable of carrying the important part of the message. For instance, a red index card with GREEN written on it.

See also

congruence, context, content, speech, nonverbal communication, indirect self-reference, ceci n'est pas une pipe