In KDE 3.2 a common menu format is introduced at https://freedesktop.org/Standards/menu-spec/

Before KDE 3.2:

It was difficult to rearrange the structure in KDE 3.2 so the new menu format:

	<Menu>
	    <Name>Office</Name>
	    <Directory>suse-office.directory</Directory>
	    <Include>
	        <Filename>Acrobat Reader.desktop</Filename>
	        <Filename>kde-kpresenter.desktop</Filename>
	        <Filename>kde-kword.desktop</Filename>
	    </Include>
	<Menu>

.menu files describing the menu structure. The files are stored in $ KDEDIR /etc/xdg/menus and /etc/xdg/menus. These store the system-wide menu structure and are controlled by $ XDG_CONFIG_DIRS . $ HOME /.config/menus stores user-specific changes to the menu structure and is controlled by $ XDG_CONFIG_HOME . For more information, see https://www.freedesktop.org/Standards/basedir-spec.

.desktop files describe the applications and are stored in: $ KDEDIR /share/applications, /usr/share/applications, /usr/local/share/applications. These are the system-wide application .desktop files which are controlled by $ XDG_DATA_DIRS .

$ HOME /.local/applications contains user-specific .desktop files and user-specific changes. It is controlled by $ XDG_DATA_HOME . For more information, see https://www.freedesktop.org/Standards/basedir-spec

.directory files describing the sub-menus are stored in: $ KDEDIR /share/desktop-directories, /usr/share/desktop-directories, /usr/local/share/desktop-directories. These are the system-wide menu .directory files, controlled by $ XDG_DATA_DIRS . The user-specific changes are stored in $ HOME /.local/desktop-directories. These are controlled by $ XDG_DATA_HOME . For more information, see https://www.freedesktop.org/Standards/basedir-spec

             <Menu>
                        <Name>Art</Name>
                        <Directory>suse-edutainment-art.directory</Directory>
                        <Include>
                                <Category>X-SuSE-Art</Category>
                        </Include>
                </Menu>

Categories=Qt;KDE;Education;X-SuSE-Art

[Desktop Entry]
Name=Art and Culture
Icon=kcmsystem

Applications not in the menu do not exist with regard to other applications or file associations: If you remove an application from the menu, KDE assumes you don't want to use it.

When applications are unwanted in the menu, either place them in .hidden menu or a dedicated menu with

NoDisplay=true

in the .directory file

$ KDEDIR /etc/xdg/menus/applications-merged/ contains kde-essential.menu which includes some essential menus that are normally not shown in the KDE menu itself:

KDE continues to support old-style menus that are defined by the directory structures in $ KDEDIR /share/applnk (system wide) and $ HOME /.kde/share/applnk (user specific). This is observed unless the .desktop file has a Categories= line. In that case the categories determine the location in the menu.

KSycoca caches menu structure and information about all available applications. You can rebuild the database with kbuildsycoca . The database which is built lives in /var/tmp/kdecache-${ USER }/ksycoca. It is automatically updated by KDED, checked during KDE login, and KDED watches for changes while logged in.

To disable watching for changes (since it may hurt over NFS) add the following to kdedrc:

[General]
CheckSycoca=false

To force regeneration, run touch $ KDEDIR /share/services/update_ksycoca .

kmenuedit is aimed at a single user setup. Changes to menu structure are saved to ~/.config/menus/applications-kmenuedit.menu, changes to applications are saved in ~/.local/share/applications/ and changes to sub-menus (icon, name) are saved in ~/.local/share/desktop-directories/. The KIOSK Admin Tool uses kmenuedit and copies the above changes to profile- or system-wide locations.