0)(f)A polygon may not overlap itself.  The side you are attempting to draw intersects with an existing side of the polygon.(f)
1)(f)Unable to close polygon.  Closing the polygon would cause the final side to intersect with an existing side of the polygon.  Click `OK` and either add another line segment so that the polygon will not overlap itself or use the escape key to cancel.(f)
2)(f)Press `esc` to cancel or any other key to close the polygon.(f)