They used to be in /usr/lib/X11/XKeysymDB or /usr/share/X11/XKeysymDB, but those have been missing from Ubuntu for a while. I've tried google, but all I get are more references to XKeysymDB or the outputs of different people's
xmodmap -pke. Where is the concise list?
Probably the best up-to-date values for key symbol definitions is to look at the source-code.
Basically its just a list of keysym names with their associated codes.
Two key keyfiles in
The main definition file:
There are a number of other header files in the same folder you can also examine.