When I try to add a Shortcut like this
System Preferences->Keyboard->Shortcuts->App Shortcuts->+->Some title->
I cannot use
^Z as Keyboard Shortcut.
It is automatically replaced by
- Shift (illustrated as arrow-up)
- Command (illustrated by the Command key symbol) followed by a
I guess this is because the shortcut is taken. But I couldn't find where. I checked all the other item above "App Shortcuts", i.e. "Accessibility", "Spotlight", ...
How can I check which app is using it and how can I force the system to use my shortcut?