Q:

Limits to Swing's Unicode support

Not long ago I asked a question attempting to identify a certain unicode character for use in a GUI.  I got the character I was looking for, but it didn't work in the Swing GUI I was building.
So, SO Community, I pose of you these questions:
What sort of limitations does Swing/Java have for Unicode support?  Are there certain subsets of unicode that are completely supported and what should I stay away from when designing in the future?
EDIT:  After applying the 'Arial Unicode MS' font as suggested by Alan Moore, everything seemed to clear up.  Seems odd that I should have to set a 3rd party font to make all the unicode characters show up though.

A:

Normally when glyphs don't display properly in a UI, it's because you're using a font that doesn't have that glyph, not because there is a problem with the unicode support in any toolkit you're using.  Very, VERY few fonts have all glyphs - you need to make sure you choose a font that has coverage in the code points you care about.

