Aug 27 2011
How to Create Better 404 Error Pages
Simple errors such as a “404 page not found” in large quantities can make search engines believe a site is not complete or under construction. As a result, they may determine the site is not worthy of strong search engine visibility. When a nonexistent page is requested from the server, the server should respond with a special “HTTP Status” header value of “404 not found,” which may also be followed by custom error-page body content.
Incorrectly configured Web servers that respond with a status header value of 200, 302 or any other erroneous value can trigger duplicate content issues for search engines because identical content (in this case, the error page content) would be available under a potentially infinite number of URLs.
