Boundaries > Create > From Selection creates a boundary line around contiguous sets of selected polygons. Sets of polygons must have been selected using selection tools (such as Edit > Select > ...) before this function is started.
Mark All button - creates a boundary line around every contiguous set of selected polygons.
Clear All button - removes every boundary line that did not exist before this function was started.
OK button - stores all boundary lines to the polygon object in the Model Manager and terminates the dialog.
Cancel button - terminates the dialog without saving any boundaries to the object in the Model Manager.