Applications list is saved at “/home/jrillet/.config/menus/applications-kmenuedit.menu”
This is an XML file.
This XML file is just a list. Only *.desktop file names are listed here.
The category (Internet, Graphics, Multimedia etc.) information files are under “/usr/share/desktop-directories/”.
The applications information files are under “/usr/share/applications/”
Note that KDE applications are under “/usr/share/applications/kde4″
Refferences:
How to edit Kickoff menu manually
KDE menu category associations – KDE Community Forums