Source : Free On-Line Dictionary of Computing

bonk/oif
     
        /bonk/, /oyf/ In the {MUD} community, it has become
        traditional to express pique or censure by "bonking" the
        offending person.  Convention holds that one should
        acknowledge a bonk by saying "oif!" and there is a myth to the
        effect that failing to do so upsets the cosmic bonk/oif
        balance, causing much trouble in the universe.  Some MUDs have
        implemented special commands for bonking and oifing.
     
        [{Jargon File}]
     
        (1998-01-18)