I basicly "googled my way to freedom", I haven't even found a table with
a complete desciption of all xmodmap entrys, e.g. that | is bar.
IIRC the YDL pages also have some docs about this.
Ah, here they are, right under my nose:
/usr/X11R6/include/X11/keysymdef.h, just remove the "XK_" from the
descriptors and you'll get what xmodmap will accept as input, e.g.
#define XK_ssharp 0x0df --> ssharp i.e. ß
$ dpkg -S /usr/X11R6/include/X11/keysymdef.h
xlibs-dev: /usr/X11R6/include/X11/keysymdef.h
-Thomas