Here is the description of the options in the Hotkeys Dialog:
• Framed Box near top:
This displays the current "Hotkey" for this item. In this example, the Command key, option key and the function key "F13" from an extended keyboard are used. While this dialog is open, just hit whatever key combination you'd like to use and it will be associated with this command and shown in this box.
Check Boxes:
• Use Large Window:
If checked, PopAddress will use a larger window, check this option only if you have at least a 13" monitor.