cheat sheets.

--- http_status_codes version 2	Wed Aug 29 23:19:55 +0000 2007
+++ http_status_codes version 3	Wed Aug 29 23:20:23 +0000 2007
@@ -1,53 +1,54 @@
 1xx Informational
   100: Continue
   101: Switching Protocols
 
 2xx Success
   200: OK
   201: Created
   202: Accepted
   203: Non-Authoritative Information
   204: No Content
   205: Reset Content
   206: Partial Content
   207: Multi-Status
 
 3xx Redirection
   300: Multiple Choices
   301: Moved Permanently
   302: Moved Temporarily (HTTP/1.0)
   302: Found (HTTP/1.1)
   303: See Other (HTTP/1.1)
   304: Not Modified
   305: Use Proxy
   306: (no longer used, but reserved)
   307: Temporary Redirect
 
 4xx Client Error
   400: Bad Request
   401: Unauthorized
   402: Payment Required
   403: Forbidden
   404: Not Found
   405: Method Not Allowed
   406: Not Acceptable
   407: Proxy Authentication Required
   408: Request Timeout
   409: Conflict
   410: Gone
   411: Length Required
   412: Precondition Failed
   413: Request Entity Too Large
   414: Request-URI Too Long
   415: Unsupported Media Type
   416: Requested Range Not Satisfiable
   417: Expectation Failed
+  422: Unprocessable Entity
 
 5xx Server Error
   500: Internal Server Error
   501: Not Implemented
   502: Bad Gateway
   503: Service Unavailable
   504: Gateway Timeout
   505: HTTP Version Not Supported