Inserting special symbols

[Lee Marks]

Does xfce have a preferred way to define key input sequences for entering special characters? (specifically a way to enter unicode (math) symbols via the keyboard - ie. I don't want to have to use a charmap gui)

So far I've attempted to do this by adding extra mappings to the Compose file in /usr/share/X11/locale/en_US.UTF-8. Strangely, I'm able to type in any of the originally defined key sequences in that file and get the correct character, but the custom ones that I added do not work. (and I've tried rebooting but it does not help).
Does this sound like it should work under xfce, or should I be taking a different approach?

Thanks in advance for any help.

Lee.