(SF fandom, originally as mutation of HHOK, "Ha Ha Only Kidding") A phrase (often seen abbreviated as HHOS) that aptly captures the flavour of much hacker discourse.Applied especially to parodies, absurdities, and ironic jokes that are both intended and perceived to contain a possibly disquieting amount of truth, or truths that are constructed on in-joke and self-parody.The Jargon File contains many examples of ha-ha-only-serious in both form and content.Indeed, the entirety of hacker culture is often perceived as ha-ha-only-serious by hackers themselvesto take it either too lightly or too seriously marks a person as an outsider, a wannabee, or in {larval stage}.For further enlightenment on this subject, consult any Zen master.See also AI koan.[Jargon File]