This property is only visible for Screen definitions with a NavigationType of InfoCollect or Exception.
When set true, if the containing screen definition is displayed as the user navigates within the application, rather than displaying as another screen, the contents of the screen's Message[xxx] fields will be read and displayed in a client side Sticky Note while displaying the next screen after the InfoCollect or Exception screen is entered-through by the task framework.
In the case of an InfoCollect navigation type, generally the sticky note will appear over the next screen after the InfoCollect. In the case of an Exception navigation type, presumably the note will be displayed over the prior screen, which is returned to after the exception screen is displayed.