Keysyms for Unicode values

I've noticed that for the most part, XKeysym values are just 
the Unicode value of the character.  However, there are
obviously Unicode values which would overlap keysyms
in the 0xFE00 to 0xFFFF range which would conflict.

I've also noticed references to passing keysyms with
the 0x01000000 bit set to mean that the lower part of
the keysym is a Unicode value.

So my question is, for what Unicode values do I _need_ to
use the 0x01000000 bit and what ones should I not?
I assume that if just set it for everything, old X clients
would be confused by it and not know what to do.


 -- Dave Williss
------
Meddle not in the affairs of dragons, 
   for you are crunchy and taste good with catsup