[Usenet] A maxim, quote, proverb, joke,
or slogan embedded in one's sig block and intended to convey
something of one's philosophical stance, pet peeves, or sense of
humor. "Calm down, it's only ones and zeroes."
ig block: /sig blok/ [UNIX; often written `.sig' there] n.
Short for `signature', used specifically to refer to the
electronic signature block that most UNIX mail- and news-posting
software will {automagically} append to outgoing mail and news....