ha ha only serious [from SF fandom, orig. as mutation of HHOK,

ha ha only serious

[from SF fandom, orig. as mutation of
HHOK, `Ha Ha Only Kidding'] A phrase (often seen abbreviated as
HHOS) that aptly captures the flavor 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. This lexicon 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
master. See also hacker humor, and AI koans.