10.4.14 413 Request Entity Too Large

   The server is refusing to process a request because the request
   entity is larger than the server is willing or able to process. The
   server may close the connection to prevent the client from continuing
   the request.

   If the condition is temporary, the server SHOULD include a Retry-
   After header field to indicate that it is temporary and after what
   time the client may try again.

10.4.15 414 Request-URI Too Long

   The server is refusing to service the request because the Request-URI
   is longer than the server is willing to interpret. This rare
   condition is only likely to occur when a client has improperly
   converted a POST request to a GET request with long query
   information, when the client has descended into a URL "black hole" of
   redirection (e.g., a redirected URL prefix that points to a suffix of
   itself), or when the server is under attack by a client attempting to
   exploit security holes present in some servers using fixed-length
   buffers for reading or manipulating the Request-URI.

10.4.16 415 Unsupported Media Type

   The server is refusing to service the request because the entity of
   the request is in a format not supported by the requested resource
   for the requested method.








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RFC 2068                        HTTP/1.1                    January 1997


10.5 Server Error 5xx

   Response status codes beginning with the digit "5" indicate cases in
   which the server is aware that it has erred or is incapable of
   performing the request. Except when responding to a HEAD request, the
   server SHOULD include an entity containing an explanation of the
   error situation, and whether it is a temporary or permanent
   condition. User agents SHOULD display any included entity to the
   user. These response codes are applicable to any request method.

10.5.1 500 Internal Server Error

   The server encountered an unexpected condition which prevented it
   from fulfilling the request.

10.5.2 501 Not Implemented

   The server does not support the functionality required to fulfill the
   request. This is the appropriate response when the server does not
   recognize the request method and is not capable of supporting it for
   any resource.

10.5.3 502 Bad Gateway

   The server, while acting as a gateway or proxy, received an invalid
   response from the upstream server it accessed in attempting to
   fulfill the request.

10.5.4 503 Service Unavailable

   The server is currently unable to handle the request due to a
   temporary overloading or maintenance of the server. The implication
   is that this is a temporary condition which will be alleviated after
   some delay. If known, the length of the delay may be indicated in a
   Retry-After header.  If no Retry-After is given, the client SHOULD
   handle the response as it would for a 500 response.

     Note: The existence of the 503 status code does not imply that a
     server must use it when becoming overloaded. Some servers may wish
     to simply refuse the connection.

10.5.5 504 Gateway Timeout

   The server, while acting as a gateway or proxy, did not receive a
   timely response from the upstream server it accessed in attempting to
   complete the request.





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RFC 2068                        HTTP/1.1                    January 1997


10.5.6 505 HTTP Version Not Supported

   The server does not support, or refuses to support, the HTTP protocol
   version that was used in the request message. The server is
   indicating that it is unable or unwilling to complete the request
   using the same major version as the client, as described in section
   3.1, other than with this error message. The response SHOULD contain
   an entity describing why that version is not supported and what other
   protocols are supported by that server.