caption                                          (Assignable)

        Contains a character string that describes the radio button on the
        screen. When present, the & character specifies that the
        character immediately following it in the caption is the radio
        button's accelerator key. The accelerator key provides a quick and
        convenient mechanism for the user to move input focus from one radio
        button to another.  The user performs the selection by pressing an
        accelerator key.  The case of an accelerator key is ignored.