Every request irrespective of the input content type will return an XML response (content type text/xml). If an application exception occurs during the execution of the request then the server will respond with an HTTP status code 500, however some requests will respond with an HTTP status code of 200 even if errors have occurred during the processing of the document. 200 OK is the default status code for any successful request.
The response for a successful request will look similar to the following
<!-- if GET request then information requested will follow -->
If an error occurs during the request, the following response will be returned
<ErrorDescription>A detailed explanation of the error</ErrorDescription>