= D =
doubled sig [Usenet] n.
A sig block that has been
included twice in a Usenet article or, less commonly, in an
electronic mail message. An article or message with a doubled sig
can be caused by improperly configured software. More often,
however, it reveals the author's lack of experience in electronic
communication. See B1FF, pseudo.
--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.