It actually is valid - an node is allowed to have mixed content. This snippet will give rise to a schema like:

<?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="page">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="content">
          <xs:complexType mixed="true">
            <xs:sequence>
              <xs:element name="div">
                <xs:complexType>
                  <xs:simpleContent>
                    <xs:extension base="xs:string">
                      <xs:attribute use="required" type="xs:string" na
+me="class" />
                    </xs:extension>
                  </xs:simpleContent>
                </xs:complexType>
              </xs:element>
            </xs:sequence>
          </xs:complexType>
        </xs:element>
      </xs:sequence>
      <xs:attribute use="required" type="xs:unsignedByte" name="id" />
    </xs:complexType>
  </xs:element>
</xs:schema>
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However this is certainly not what was intended - if the contents of <content /> are to be taken literally it should be a CDATA section.

/J\