The idea that humor and jokes are a violation of the co-operation (CP) has a widespread literature, reviewed and systematized in Attardo. Attardo reports this discussion and anticipates further discussion of a hierarchy of principles that eventually appeared as Attardo. The maxims and the CP have a peculiar status in Grice's opus. Due to Grice's infelicitous wording many readers have misunderstood the relationship between the maxims and the CP and come to believe the logically impossible idea that one could violate given maxim while still following the CP. Thomas quotes questioning in court of law, in which speakers are not expected to self-incriminate; eulogies and obituaries, which will generally omit negative information about the deceased. The recognition of violation and the attribution to the speaker of the pro-social intention to amuse will cause the interlocutors to recognize the metamessage "this is play" and they may start keying the situation for humor or sanction it as an unwarranted use of humor.