Giving voice to silent function keys

[Kevin O'Gorman]

I'm trying to customize vim in various ways.  I've run into a puzzle
with function keys, in that some of them don't do anything at all with
certain modifier keys.  I'm running under gnome 2 on Ubuntu 11.04.

I'm using the showkey(1) command to get the ASCII sequence from
combinations of keys, except Alt-Control or Alt-Control-Shift, all of
which switch console windows.

I've found that most of them send an escape sequence, a few of them do
something special, and a few are silent.
The silent ones are control-F1, Alt-F5, Alt-F6, Alt-F7, Alt-Shift-F6
and Alt-Shift-F7.

The question for each of those 6 is the same:
  1) Does the key actually do something, and I just didn't notice.
  2) Is there a way to make the key available to an application like Vim?

-- 
Kevin O'Gorman, PhD