MySQL 9.5 Reference Manual Including MySQL NDB Cluster 9.5
A MultiSurface is a geometry collection
composed of surface elements. MultiSurface
is a noninstantiable class. Its only instantiable subclass is
MultiPolygon.
MultiSurface
Assertions
Surfaces within a MultiSurface have no
interiors that intersect.
Surfaces within a MultiSurface have
boundaries that intersect at most at a finite number of
points.