By default F10 on Xfce activates the window File menu and so cannot be used as a shortcut in any program.
I already looked in the Window Manager and Keyboard settings pages and no F10 key binding is listed.
How can I re-map/un-map this?
Xfce provides a way to disable the key binding from the Settings Editor.
This will work only for GTK+ 2 applications, given that "gtk-menu-bar-accel" has been deprecated in GTK+ 3 (since version 3.10). As a result, user might have no choice but to disable the key binding per application, which may also depend on which toolkit in use.
Go to Applications Menu > Settings > Settings Editor. Xfce 4.10 or newer provides another way to access by Settings Manager > Other - Settings Editor.
In the Settings Editor:
F10 (leave it blank) and click
The final step will disable the key binding for activating the menu bar.
Custom keys: User can also change the key binding to something else. For example, changing the value to
<Control>F12 will re-map to Ctrl+F12 key combination to activate the menu. Try with any key bindings using
<Shift> and other keys. More clues are found under "Channel: xfce4-keyboard-shortcuts" and under "Property".
Restore to default: In the Settings Editor, click Reset button that is located at the right-most icon, either at near-bottom of window (Xfce 4.10 or newer) or, on top of "Property" column (Xfce 4.8).
Precaution (Xfce 4.8): In older Xfce, clicking Reset button will cause the entire row of "MenuBarAccel" to be removed at all. To avoid this, double-click on the row again and change the value to
F10 to restore.
In case user have accidentally deleted the property, create again the property as follows. Click New and re-register the property in the "New Property" dialog with the settings quoted as above.
Xfce can still disable the key binding for GTK+ 2 applications, such as Orage and Xournal. Given that many applications are now GTK+ 3, the setting will be less and less relevent in newer Xfce.