Specifying a Set of Acceptable Values : enumeration « XML Schema « XML Tutorial

1. XML Tutorial
2. XML Schema
3. enumeration

<?xml version="1.0"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  targetNamespace="http://www.java2s.com" xmlns="http://www.java2s.com"
  elementFormDefault="qualified">

  <xsd:element name="continent">
    <xsd:simpleType>
      <xsd:restriction base="xsd:string">
        <xsd:enumeration value="Asia" />
        <xsd:enumeration value="Africa" />
        <xsd:enumeration value="Australia" />
        <xsd:enumeration value="Europe" />
        <xsd:enumeration value="North America" />
        <xsd:enumeration value="South America" />
        <xsd:enumeration value="Antartica" />
      </xsd:restriction>
    </xsd:simpleType>
  </xsd:element>
</xsd:schema>


Data.xml: The continent element can now contain any single one of these values. 
<?xml version="1.0"?>
<continent>Asia</continent>

You can use the xsd:enumeration facet with all simple types except boolean.
Each enumeration value must be unique.
Enumeration values may contain white space.