Some examples for restriction possibilities

• length, minLength, maxLength for strings
• minInclusive, maxInclusive, minExclusive, maxExclusive for numerical values
• duration, period for time related types
• pattern (regular expressions) for strings
• enumeration for all
• etc

For example, the type:

  <simpleType name="Dutch_ZIP_Code">
    <restriction base="string">
      <pattern value="\d{4} {0,1}[A-Z]{2}"/>
    </restriction>
  </simpleType>

defines the Dutch ZIP codes of the type "1183 NW" or "1183NW".