<xs:element name="source">
    <xs:annotation>
        <xs:documentation>
				atom:source is used to preserve metadata of a feed
				when
				an entry is copied from a feed to another feed.
			</xs:documentation>
    </xs:annotation>
    <xs:complexType>
        <xs:choice minOccurs="0" maxOccurs="unbounded">
            <xs:element ref="atom:author" />
            <xs:element ref="atom:category" />
            <xs:element ref="atom:contributor" />
            <xs:element ref="atom:generator" />
            <xs:element ref="atom:icon" />
            <xs:element ref="atom:id" />
            <xs:element ref="atom:link" />
            <xs:element ref="atom:logo" />
            <xs:element ref="atom:rights" />
            <xs:element ref="atom:subtitle" />
            <xs:element ref="atom:title" />
            <xs:element ref="atom:updated" />
            <xs:group ref="atom:extensionElement" />
        </xs:choice>
        <xs:attributeGroup ref="atom:atomCommonAttributes" />
    </xs:complexType>
</xs:element>