When an error occurs, the header information contains:
Content-Type: application/*, which may be in HTML or text format
HTTP status code 3xx, 4xx, or 5xx. For details, see Table 1.
The response body also contains information about the error. The following example is an error response body in an authentication failure.
<html><h1>Unauthorized</h1><p>This server could not verify that you are authorized to access the document you requested.</p></html>