<element name="addressBook" ns="http://www.example.com" xmlns="http://relaxng.org/ns/structure/1.0"> <zeroOrMore> <element name="card" ns="http://www.example.com"> <element name="name" ns="http://www.example.com"> <text/> </element> <element name="email" ns="http://www.example.com"> <text/> </element> </element> </zeroOrMore> </element>