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).