HTTP Status Codes:
HTTP status codes are returned by web servers to indicate the status of a request. Codes 200 and 304 are used to tell the browser the page can be viewed. All other codes generates hits and traffic 'not seen' by the visitor. For example a return code 301 or 302 will tell the browser to ask another page. The browser will do another hit and should finally receive the page with a return code 200 and 304. All codes that are 'unseen' traffic are isolated by Logstats in the HTTP Status report chart, enabled by the directives ShowHTTPErrorsStats. in config file. You can also change value for 'not error' hits (set by default to 200 and 304 with the ValidHTTPcodes directive. The following table outlines all status codes defined for the HTTP/1.1 draft specification outlined in IETF rfc 2068.
They are 3-digit codes where the first digit of this code identifies the class of the status code and the remaining 2 digits correspond to the specific condition within the response class. They are classified in 5 categories: