SOAPDoc Fault Section
In the body of a SOAP XML response document, you can define a fault section. Generally this is used if in an inbound message has been processed and some sort of error occurred. The text of the message gives further information about the error.
Use the AddFault method to add a fault code and a fault string to the body of a SOAPDoc. Only one fault section can be set within one SOAP XML document.
If you receive a response message that contains a fault, use the FaultCode and FaultString methods to return these values.