I found this page: https://help.ubuntu.com/community/ComposeKey
With the default settings <Right ALT> and <SHIFT>+<Right ALT> I get a few
special characters to work but cannot seem to use the alternate levels of
Some specific examples that work: (Hurray!!)
<SHIFT>+<Right ALT> then <SHIFT>+"e" then apostrophe ==> capital-E with acute accent
<SHIFT>+<Right ALT> then apostrophe then "e" ==> lower-e with acute accent
<SHIFT>+<Right ALT> then <SHIFT>+"u" then double-quote ==> capital-U with umlaut
<SHIFT>+<Right ALT> then double-quote then "U" ==> lower-e with umlaut
There are lots of others that I cannot get to work. I suspect that I simply do not know
which characters to use for the desired result. For example, I expected to combine
the letter-c with the letter-n to get a cidilla (small hook beneath) the letter-n.
Instead I got a small letter-v (inverted circumflex) over the letter-n.
[indent]NOTE -- This stuff is really hard to post about because I have little faith that the site content manager (database) will properly store and retrieve the various "special characters". I've had that problem even though sites claim to use UTF-8 or UTF-16 character sets. There must be some other detail(s) needed to guarantee that special characters work round trip.
There are other characters -- the German double-s that looks like a capital-B, single-character fractions, merged capital-A+capital-E, paragraph mark, double-<, double-> and so on -- that I cannot get to appear at all.
I'd expect that somewhere there are tables or configuration for all of this. The whole magilla must be pretty complex given:
- hardware keypress to kernel driver (is that "scancode"?)
- kernel drive to X11 input (is that "key code"?)
- X11 input through application storage
- application storage through X11 output to display
- display character cell or bitmap representation
... (grin) if you could only find the doc files.