About null...

Hello,

Out of a XML Schema perspective, xsi:nil="true" is used to represent a null value, String or otherwise. This is not the same as sending an empty element (). The difference is that an element with xsi:nil has no value, whereas the empty element has an empty value. For an xsd:string type this is an empty string. Many XSD types do not allow empty values, such as xsd:int, but they can still be null if the schema allows it (by setting nillable="true").

Regards,
Dain
eviware