1  <?xml version="1.0" encoding="ISO-8859-1" ?>
 2  
 3  <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
 4  
 5    <xs:element name="foo">
 6      <xs:complexType>
 7          <xs:choice minOccurs="0" maxOccurs="unbounded">
 8          
 9            <xs:element name="barA"  >
10              <xs:complexType>            
11                <xs:attribute name="attr" type="xs:string" use="required" />                            
12              </xs:complexType>
13            </xs:element>
14            
15            <xs:element name="barB" >
16              <xs:complexType>
17                <xs:attribute name="attr" type="xs:string" use="optional" />
18              </xs:complexType>  
19            </xs:element>
20            
21            <xs:element name="barC" >
22              <xs:complexType>
23                <xs:attribute name="attr" type="xs:string" use="prohibited" />
24              </xs:complexType>  
25            </xs:element>
26            
27          </xs:choice>
28      </xs:complexType>
29    </xs:element>
30  
31  </xs:schema>
32