Specify an icon that will be associated with all the files handled by that ProgID. Choose a file containing icons by using thebutton, and select an icon from the available icons from the drop-down list box. Press to revert to no icon.
Mac OS X
Specify an icon that will be associated with this file type in a Mac OS X package. Choose a file containing a Mac OS X icon by using thebutton.
Check the “Be the default application associated with these file types” check box to make your application the default one for that file type.