OSU
= O =
OTOH
OT //
[Usenet: common] Abbreviation for "off-topic".
This is used to respond to a question that is inappropriate for the
newsgroup that the questioner posted to. Often used in an
HTML-style modifier or with adverbs.
--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.