The geometry type of a feature class can be specified in a .gfs
file used by OGR to map from a GML document to a simple feature schema. The following numbers can be used to specify a specific geometry type:
-2147483647 Point25D
-2147483646 LineString25D
-2147483645 Polygon25D
-2147483644 MultiPoint25D
-2147483643 MultiLineString25D
-2147483642 MultiPolygon25D