Reading firefox's .desktop file /usr/share/applications/firefox.desktop I believe this is needed:
X-Ayatana-Desktop-Shortcuts=NewWindow; [NewWindow Shortcut Group] Name=Open a New Window Exec=terminator TargetEnvironment=Unity
Reading firefox's .desktop file /usr/share/ applications/ firefox. desktop I believe this is needed:
X-Ayatana- Desktop- Shortcuts= NewWindow; nt=Unity
[NewWindow Shortcut Group]
Name=Open a New Window
Exec=terminator
TargetEnvironme