Input string
The String field is an input field in which you specify the key sequence that you want the action to perform.
To specify a key that causes a character to be displayed (such as a, b, c, #, &, and so on), type the key itself.
To specify a key from the Actions Keys listbox, scroll the list to the key you want (such as [backspace]) and click Insert Action Key. The name of the key enclosed by square brackets appears at the next input position in the String field. Please notice that the keys in the Action Keys listbox are not listed alphabetically throughout. You might have to keep scrolling down the list to find the key you want.
Another way to specify an action key is just to type the name itself into the String input field, surrounded by square brackets (for example, [backspace]).
[copy] [mark right]
[copyappend] [mark up]
[cut] [paste]
[mark down] [pastenext]
[mark left] [unmark]
For other keys see Mnemonic keywords for the Input action.