Specifies the Resource ID of an icon to use as the overlay. See description for hIcon for details.
A pointer to a string that provides an alt text version of the information conveyed by the overlay, for accessibility purposes.
The handle of an icon to use as the overlay. This should be a small icon, measuring 16x16 pixels at 96 dots per inch (dpi). If an overlay icon is already applied to the taskbar button, that existing overlay is replaced. This value can be NULL. How a NULL value is handled depends on whether the taskbar button represents a single window or a group of windows. It is the responsibility of the calling application to free hIcon when it is no longer needed.