Ignoring a key event completely

[Michael Schutte <m.schutte.jr@gmail.com>]

Hi everybody,

The XKB layout I’m using [1] defines an additional modifier, the
Navigation key.  Whenever I press it, Emacs responds by beeping and
printing “<key-17> is undefined”.  I can suppress this by
global-set-keying it to 'ignore, but this does not turn it off
completely.  In particular:

 * Hitting the key still interrupts Isearch, which is very annoying.
 * M-Nav, C-Nav and C-M-Nav also need to be 'ignored, which does not
   seem very elegant to me.
 * Messages appearing in the echo area are nuked when I press Nav (this
   is minor, of course, but you get the idea).

So, I’m looking for a way to make Emacs completely forget about the key,
to make it as no-oppy as Shift, Ctrl, etc., but I simply can’t find out
how to do this on my own.  Could anyone give me a clue?

[1] <https://neo.eigenheimstrasse.de/svn/linux/X/de>; grep for Mod4

Thanks in advance,
-- 
Michael Schutte <m.schutte.jr@gmail.com>