kaddressbook

Of course in ~/.kde/share/apps, but if you have one hundred kde apllications and the programmers didn't manage to come up with a descriptive name for the configuration directory, you are in trouble. KAdressbook stores the data in ~/.kde/share/apps/kabc Additonally there might be for all applications (and there is for KAdressbook) the rc configuration file in ~/.kde/share/config/ ~/.kde/share/config/kaddressbookrc