The interiors of two Polygon values that are elements of a MultiPolygon may not intersect.
The boundaries of any two Polygon values that are elements of a MultiPolygon may not cross and may touch at only a finite number of points. (Crossing is also forbidden by the preceding assertion.)
A MultiPolygon may not have cut lines, spikes or punctures. A MultiPolygon is a regular, closed point set.
The interior of a MultiPolygon composed of more than one Polygon is not connected. The number of connected components of the interior of a MultiPolygon is equal to the number of Polygon values in the MultiPolygon.