http://www.w3.org/2001/XMLSchema-instance
http://help.eclipse.org/indigo/index.jsp?topic=%2Forg.eclipse.wst.xmleditor.doc.user%2Ftopics%2Ftxsityp.html
http://zvon.org/xxl/XMLSchemaTutorial/Output/ser_over_st1.html
http://zvon.org/xxl/xmlSchema2001Reference/Standard//xmlschema-2.html#integer