200 OK - This class of status code indicates that the client's request was successfully received, understood and accepted.
301 Moved Permanently - The URL you requested has moved permanently, all further queries shoud be directed to the new location. If an old page is no longer valid and you have a new one in it's place, you should use 301-redirects whenever possible. The search engines will then replace the old URL with the new one and transfer any possible "value" of the old URL to the new one.
302 Found: Moved Temporarily - The server has found a temporary redirection. Since this is temporary, this URL should be used once again for the next time (not the new URL).
304 Not Modified - You shouldn't be seeing this here - it only returns 304 when the client asks for a newer version of a URL.
307 Temporary Redirect - This is similar to a 302 redirect, the redirection is temporary and the existing URL should continue to be used.
400 Bad Request - The server didn't understand what you were looking for.
401 Unauthorized - The server does not want to give you access to this content without authentification.
403 Forbidden - The server does not want to help you. period. Authentification will not help in this case.
404 Not Found - Oops, the file you were looking for is not found. Search engines need a 404 in order to know which URLs are valid and which are not. In order to keep any value of the old URLs, you should keep a dummy page at the location of the old URL and 301-redirect from there to the new URL (assuming you have a new one). [More information on Google and 404-errors]
405 Method not allowed
410 Gone - The URl you were looking for is... gone. This is similar to 404.
413 Request entity too large
415 Unsupported media type
417 Expectation failed
500 Internal server error - Your server is not answering to your requests properly. Contact your System-Administrator or Host
Web Page Status Return Codes
Linear Mode
