SIG

SIG /sig/ n.  (also common as a prefix in combining forms)
   A Special Interest Group, in one of several technical areas,
   sponsored by the Association for Computing Machinery; well-known
   ones include SIGPLAN (the Special Interest Group on Programming
   Languages), SIGARCH (the Special Interest Group for Computer
   Architecture) and SIGGRAPH (the Special Interest Group for Computer
   Graphics).  Hackers, not surprisingly, like to overextend this
   naming convention to less formal associations like SIGBEER (at ACM
   conferences) and SIGFOOD (at University of Illinois).