ACCELERATOR3 action attribute
The ACCELERATOR3 is an action attribute defining the third
  accelerator key for an action.
Syntax
Syntax 1 (Dialog action handlers): N/A
Syntax 2 (ACTION DEFAULTS section in form files)
ACCELERATOR3 = key
    Syntax 3 (Global .4ad action defaults file)
acceleratorName3 = "key"
    - key defines the accelerator key.
 
Usage
The ACCELERATOR3 attribute defines the keyboard combination
that can be pressed by the user to send an action to the program.
Important: This attribute is provided for specific cases, consider using only
            one accelerator per
          action.