Birds of a Feather: This idiom is a shortening of the proverb "Birds of a feather flock together.", meaning that people (birds) of the same kind or interest (of a common feather) enjoy spending time (flocking) together. This proverb is believed to date back as far as Greek and Roman times, but has become commonly used as jargon by various groups since the nineteenth century. In the world of computing, BoF (Birds Of a Feather) can refer to: An informal discussion group. Unlike Special Interest Groups or Working groups, BoFs are informal and often formed in an ad-hoc manner. The acronym is used by the Internet Engineering Task Force (IETF) to denote initial meetings of members interested in a particular issue. A BoF session, an informal meet-up at conferences, where the attendees group together based on a shared interest and carry out discussions without any pre-planned agenda.