<complexType name="AbstractGMLType" abstract="true">
	<annotation>
		<documentation>All complexContent GML elements are directly or indirectly derived from this abstract supertype 
to establish a hierarchy of GML types that may be distinguished from other XML types by their ancestry. 
Elements in this hierarchy may have an ID and are thus referenceable.</documentation>
	</annotation>
	<sequence>
		<group ref="gml:StandardObjectProperties"/>
	</sequence>
	<attribute ref="gml:id" use="optional"/>
</complexType>