The requested resource could not be found but may be available again in the future. Subsequent requests by the client are permissible. Thank you Nevada Hamaker (www.flickr.com/photos/nevadahamaker/) for letting me use Miki's pic :-D
The server timed out waiting for the request. According to W3 HTTP specifications: "The client did not produce a request within the time that the server was prepared to wait. The client MAY repeat the request without modifications at any later time."
Thank you, Sarah for letting me use the awesome pic of Oliver :-) www.flickr.com/photos/srhbth/487911150/ This status code is not specified in any RFCs, but is used by some HTTP proxies to signal a network connect timeout behind the proxy to a client in front of the proxy.