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