Source : Free On-Line Dictionary of Computing

cokebottle
     
        /kohk'bot-l/ Any very unusual character, particularly one you
        can't type because it isn't on your keyboard.  {MIT} people
        used to complain about the "control-meta-cokebottle" commands
        at {SAIL}, and {SAIL} people complained about the
        "{altmode}-altmode-cokebottle" commands at {MIT}.  After the
        demise of the {space-cadet keyboard}, "cokebottle" faded away
        as serious usage, but was often invoked humorously to describe
        an (unspecified) weird or non-intuitive keystroke command.  It
        may be due for a second inning, however.  The {OSF}/{Motif}
        {window manager}, "{mwm}", has a reserved keystroke for
        switching to the default set of keybindings and behaviour.
        This keystroke is (believe it or not) "control-meta-bang" (see
        {bang}).  Since the exclamation point looks a lot like an
        upside down Coke bottle, {Motif} hackers have begun referring
        to this keystroke as "cokebottle".
     
        See also {quadruple bucky}.
     
        [{Jargon File}]
     
        (1995-01-04)