These are the sub-properties that determine what a collapsed 'Flow Collapse Button' looks like, if it uses an icon, and if it has bubble help.

Button HTML 

Optional. Specify the text to show on the button when the Panels before this Panel are expanded (i.e. not docked or hidden). If you don't specify a value a default the << symbol will be used.

Button icon 

Button pressed icon 

Button hover icon 

Button bubble icon