Compose <MultiKey> HOWTO question ??

[William Case]

Hi;

I am not sure who is the boss, Fedora7, or Gnome 2.18.3, or Xwindows, of
composing multikey characters like ¢, ± or é ?

Some of my compose characters such as vulgar fractions seem to be
missing.  Is there a list or table that shows which ones I have
available and where would I find that list on my machine?  Is there a
way to add items to the list?

I have found what I think is the list of all possible compose codes at:
http://webcvs.freedesktop.org/xorg/xc/nls/Compose/en_US.UTF-8?view=co

If so, how would I add codes from here to my compose code list?

-- 
Regards Bill