geometryAggregates.xsd See ISO/DIS 19136 12.3. Geometric aggregates (i.e. instances of a subtype of gml:AbstractGeometricAggregateType) are arbitrary aggregations of geometry elements. They are not assumed to have any additional internal structure and are used to "collect" pieces of geometry of a specified type. Application schemas may use aggregates for features that use multiple geometric objects in their representations. GML is an OGC Standard. Copyright (c) 2007,2010 Open Geospatial Consortium. To obtain additional rights of use, visit http://www.opengeospatial.org/legal/ . gml:AbstractGeometricAggregate is the abstract head of the substitution group for all geometric aggregates. A gml:MultiSurface is defined by one or more gml:AbstractSurfaces. The members of the geometric aggregate may be specified either using the "standard" property (gml:surfaceMember) or the array property (gml:surfaceMembers). It is also valid to use both the "standard" and the array properties in the same collection. This property element contains a list of surfaces. The order of the elements is significant and shall be preserved when processing the array. A property that has a collection of surfaces as its value domain may either be an appropriate geometry element encapsulated in an element of this type or an XLink reference to a remote geometry element (where remote includes geometry elements located elsewhere in the same document). Either the reference or the contained element shall be given, but neither both nor none.