Xubuntu system menu items are controlled via files in the following directory:
This directory contains a lot of files that end in .desktop. These are the files that control what menu items appear in certain categories.
You may create your own local copies in ~/.local/share/applications
0Add New Menu Item
- Create the .desktop file of the menu item you want to add.
- Add a "Categories=" line with the one from a .desktop file of an application already in the desired category.
- To find icon:
find *.xpm | grep <application name>
find *.png | grep <application name>
find *.svg | grep <application name>