Whenever the user hits the RMB and the mouse is above the parent object, MUI will present the popup menu instead of the windows menu.
Please note that menustrips which are used as context menus must
not contain more than one <menu>
tree.
In MUI Royale 1.0 this attribute could only be used at initialization stage. Starting with MUI Royale 1.1 it has an applicability of "IS" which means that you can also change context menus at runtime. To remove a context menu completely, pass the special string "(none)" to this attribute.
See Menustrip class for an example.