<xs:element name="Circle" type="CircleType"><xs:annotation><xs:documentation>The Circle element is the circle that defines the basic size and location of a circular area.</xs:documentation></xs:annotation></xs:element>
The id attribute is the QIF id of the feature zone, used for referencing.
Source
<xs:complexType name="FeatureZoneAreaCircularType"><xs:annotation><xs:documentation>The FeatureZoneAreaCircularType defines a feature zone as circular area.</xs:documentation></xs:annotation><xs:complexContent><xs:extension base="FeatureZoneAreaBaseType"><xs:sequence><xs:element name="Circle" type="CircleType"><xs:annotation><xs:documentation>The Circle element is the circle that defines the basic size and location of a circular area.</xs:documentation></xs:annotation></xs:element></xs:sequence></xs:extension></xs:complexContent></xs:complexType>