<element name=“addressBook” xmlns=“relaxng.org/ns/structure/1.0”>
<zeroOrMore> <element name="card"> <attribute name="email"/> </element> </zeroOrMore>
</element>
<element name=“addressBook” xmlns=“relaxng.org/ns/structure/1.0”>
<zeroOrMore> <element name="card"> <attribute name="email"/> </element> </zeroOrMore>
</element>