<xs:schema xmlns:xs='http://www.w3.org/2001/XMLSchema'>

 <xs:element name="addresses">
	<xs:complexType>
	 <xs:sequence>
		 <xs:element ref="address" minOccurs='1' maxOccurs='unbounded'/>
	 </xs:sequence>
 </xs:complexType>
</xs:element>

 <xs:element name="address">
	<xs:complexType>
	 <xs:sequence>
		 <xs:element ref="name" minOccurs='0' maxOccurs='1'/>
		 <xs:element ref="street" minOccurs='0' maxOccurs='1'/>
	 </xs:sequence>
	</xs:complexType>
 </xs:element>

 <xs:element name="name" type='xs:string'/>
 <xs:element name="street" type='xs:string'/>
</xs:schema>