hello,
i'm using kde-4.3.3
and i'd like to add some international characters to my us layout ( i have also a bulgarian one ).
i've found this document which is exactly what i need

http://www.astro.ufl.edu/it/docs/intl-keyboard.html

but in kde4 there is no layout called "U.S. English w/ISO9995-3"
i've tried using olpc2 but is not the same thins.
also the 3rd level keys work in konsole and skype but not in firefox or thunderbird.
International (with dead key) works fine, but i don't find it handy.
any tips?

If I understand you correctly, you're trying to enable to Compose key.

If so, have a look here.

hi,
i'll split my question in two.
1. How do i add or modify an existing layout? (U.S. English w/ISO9995-3)

2. Enabling Compose key works only in konsole and skype
NOT in firefox, thunderbird, bluefish ...
why is that?

I don't know. It works fine for me both wit Qt and Gtk+ apps...

never mind the second question. it works in firefox also, just one has to release the compose key before pressing the second and then the third

ex.
compose THAN ` THAN a

konsole i did

compose + ` THAN a

That's correct; Compose is not a modifier key.

I don't know about the layouts, though, because I've never had the need to change them.