+ <xs:complexType name="about">
+ <xs:all>
+ <xs:element name="author" type="xs:string" minOccurs="0"/>
+ <xs:element name="email" type="xs:string" minOccurs="0"/>
+ <xs:element name="webpage" type="xs:string" minOccurs="0"/>
+ <xs:element name="comment" type="xs:string" minOccurs="0"/>
+ </xs:all>
+ </xs:complexType>
+