BOF

BOF /B-O-F/ or /bof/ n.  Abbreviation for the phrase
   "Birds Of a Feather" (flocking together), an informal discussion
   group and/or bull session scheduled on a conference program.  It is
   not clear where or when this term originated, but it is now
   associated with the USENIX conferences for UNIX techies and was
   already established there by 1984.  It was used earlier than that
   at DECUS conferences and is reported to have been common at SHARE
   meetings as far back as the early 1960s.