SIG

1. Abbreviation for special interest group.
1. Within a given technical discipline or area of knowledge, a circle of individuals or organizations having an intensified interest in a narrower facet of the general area.
2. In networking, particularly involving Internet applications, a group of individuals or organizations that sponsor, e.g., IRC channels, mailing lists, or Web sites for the purpose of promoting interest in, or advancement of, a particular area of knowledge.