The normalizedString datatype is derived from the string type : normalizedString « XML Schema « XML Tutorial

1. XML Tutorial
2. XML Schema
3. normalizedString

<!-- schema -->
<xsd:element name="myString">
  <xsd:simpleType>
   <xsd:restriction base="xsd:normalizedString">
    <xsd:maxLength value="50"/>
   </xsd:restriction>
  </xsd:simpleType>
</xsd:element>

<!-- instance document -->
<myString>Heres one. </myString>