<xs:element name="Boundary">
    <xs:annotation>
        <xs:documentation>The boundary region contains a 2D north/east or 3D north/east/elev list of points that define the geometry.</xs:documentation>
        <xs:documentation>is identified by the "name" attribute.</xs:documentation>
        <xs:documentation>If the "edgeTrim" attribute is true the faces are trimmed at the boundary edge, otherwise faces are not trimmed</xs:documentation>
        <xs:documentation>and must exist entirely within the boundary.</xs:documentation>
    </xs:annotation>
    <xs:complexType>
        <xs:sequence>
            <xs:choice>
                <xs:element ref="PntList2D" />
                <xs:element ref="PntList3D" />
                <!-- Here PntList2D represents 2D planametric coordinate pairs expressed as space delimited Northing Easting pairs. -->
            </xs:choice>
            <xs:element ref="Feature" minOccurs="0" maxOccurs="unbounded" />
        </xs:sequence>
        <xs:attribute name="bndType" type="surfBndType" use="required" />
        <xs:attribute name="edgeTrim" type="xs:boolean" use="required" />
        <xs:attribute name="area" type="xs:double" />
        <xs:attribute name="desc" type="xs:string" />
        <xs:attribute name="name" type="xs:string" />
        <xs:attribute name="state" type="stateType" />
    </xs:complexType>
</xs:element>