sig virus

from Jargon File (4.4.4, 14 Aug 2003)
sig virus
 n.

   A parasitic {meme} embedded in a {sig block}. There was a {meme
   plague} or fad for these on Usenet in late 1991. Most were equivalents
   of "I am a .sig virus. Please reproduce me in your .sig block.". Of
   course, the .sig virus's memetic hook is the giggle value of going
   along with the gag; this, however, was a self-limiting phenomenon as
   more and more people picked up on the idea. There were creative
   variants on it; some people stuck `sig virus antibody' texts in their
   sigs, and there was at least one instance of a sig virus eater.
    
from The Free On-line Dictionary of Computing (8 July 2008)
sig virus

   A parasitic {meme} embedded in a {sig block}.  There was a
   {meme plague} or fad for these on {Usenet} in late 1991.  Most
   were equivalents of "I am a .sig virus.  Please reproduce me
   in your .sig block.".  Of course, the .sig virus's memetic
   hook is the giggle value of going along with the gag; this,
   however, was a self-limiting phenomenon as more and more
   people picked up on the idea.  There were creative variants on
   it; some people stuck "sig virus antibody" texts in their
   sigs, and there was at least one instance of a sig virus
   eater.

   [{Jargon File}]
    

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