Managing Menu choices on the desktop in F21

[Max Pyziur]

Greetings,

After installing F21 on a x64 desktop, I proceeded to also install non-RPM 
software.

For these types of software to appear in the menus, there are *.desktop 
files in the directory:
/usr/share/applications

The software that I installed is OpenJUMP, a java-based GIS package 
somewhat like Quantum-GIS (QGIS Desktop).

In the *.desktop file, there is a line that controls the submenu 
placement; it looks like this:
Categories=Education;Geography;Science;


Howver, in this case OpenJUMP has also become it's own Category.

I would like to eliminate this, but the places that I've looked so far 
(Settings -> Desktop) don't offer control of this.

I'm using Xfce as a desktop; but this phenomenon also appears in MATE, 
Gnome, and Gnome Classic.


Where would I look or what file should I edit?

Much thanks,

Max Pyziur
pyz at brama.com