Use of enumeration

Example: CWI has two buildings; the choice of the building should be restricted to one of the two:

  <simpleType name="Building_Type">
    <restriction base="string">                   
      <xsd:enumeration value="Main"/>
      <xsd:enumeration value="Secondary"/>
    </restriction>
  </simpleType>

Ie, the following is valid:

  <Building>Main</Building>

but

  <Building>Third</Building>

is not (although valid XML and valid for the DTD)