Types of modifier key that can be active during an event.
                Note that there can be multiple modifiers active at once.
                Additional resources: Event, GUI Scripting Guide.
            
| Property | Description | 
|---|---|
| None | No modifier key pressed during a keystroke event. | 
| Shift | Is Shift held down? | 
| Control | Is Control key held down? | 
| Alt | Is Alt/Option key held down? | 
| Command | Is Command/Windows key held down? | 
| Numeric | Is the current keypress on the numeric keyboard? | 
| CapsLock | Is Caps Lock on? | 
| FunctionKey | Determines whether the current key press is a function key. |