 <schema xmlns="http://www.w3.org/2001/XMLSchema"
         xmlns:b="http://businesscard.org"
         targetNamespace="http://businesscard.org"
         elementFormDefault="qualified">

    <element name="cardlist">
      <complexType>
        <sequence>
          <element ref="b:card" 
                   minOccurs="0" 
                   maxOccurs="unbounded"/>
        </sequence>
      </complexType>
    </element>

    <element name="card" 
             type="b:card_type"/>
 
    <complexType name="card_type">
      <sequence>
        <element name="name" 
                 type="string"/>
        <element name="email" 
                 type="string" 
                 maxOccurs="unbounded"/>
        <element name="phone" 
                 type="string" 
                 minOccurs="0"/>
      </sequence>
    </complexType>
 
  </schema>