| 401 |
Unauthorized. Include a WWW-Authenticate header field containing a challenge applicable to the requested resource. |
| 403 |
Forbidden. The request was a valid request, but the server is refusing to respond to it. 403 error semantically means "unauthorized", i.e. the user does not have the necessary permissions for the resource. |
| 404 |
Not Found. The requested resource could not be found. |
| 422 |
Unprocessable Entity. The request was well-formed but was unable to be followed due to semantic errors. |
| 500 |
Internal Server Error. An unexpected condition was encountered. |