Dictionary.net

(BOF) (From the saying "Birds of a feather flock together") Aninformal discussion group, scheduled on a conference programor formed ad hoc, to consider a specific issue or subject. Itis not clear where or when this term originated, but it is nowassociated with the USENIX conferences for Unix techiesand was already established there by 1984. It was usedearlier than that at DECUS conferences and is reported tohave been common at SHARE meetings as far back as the early1960s.