Ob-
/ob/ prefix Obligatory.
A piece of
netiquette acknowledging that the author has been straying from the newsgroup's charter topic.
For example, if a posting in alt.sex is a response to a part of someone else's posting that has nothing particularly to do with sex, the author may append "ObSex" (or "Obsex") and toss off a question or vignette about some unusual erotic act. It is considered a sign of great winnitude when one's Obs are more interesting than other people's whole postings.
[
Jargon File]
