from
The Free On-line Dictionary of Computing (8 July 2008)
ha ha only serious
HHOS
(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
themselves; to 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}]