Comment 6 for bug 1245315

Again, the Categories=<>; key is not what decides what apps go where, according to the menu-spec.

Alacarte writes to ~/.config/menus/applications.menu or similar, which should describe any user-configured overrides to the menus. If XFCE's menu implementation does not support this format, then it is not a menu-spec-compliant menu, and alacarte shouldn't be used to configure it.

You can see this file for yourself (it may also be ~/.config/menus/xfce-applications.menu -- check $XDG_MENU_PREFIX), and look at the customizations alacarte is writing to your applications.menu file.

I tested this with gnome-panel and gnome-shell, both of which use the gnome-menus library, and Alacarte's customizations came through fine for me.