A good way to keep your sites listing after a redevelopment is to use a redirect. If you are using an Apache server you can use the .htaccess file to redirect.

Redirect 301 /oldpage.html /newpage.html

But some times this isnt the best way if you have to redirect hundreds of pages. The alternative is to use a header redirect in PHP. Most web based languages such as ASP or RUBY will do the same thing but with different code.


<?php

// make this code the first line
header("Location: /newpage.php",TRUE,301); // 301 Moved Permanently to newpage.php
?>

But why do you need to use one, well the short answer is you don’t but the long answer is it can help a lot to stop duplicate content being taken off search engines and in turn help improve your SEO.
For example how often do you see urls like www.bbc.com/index.html ?

The code below will redirect any variation on your homepage to just one. it will add the www. to the domain name and remove the index.html or index.php which ever you might be using.

RewriteEngine On
RewriteCond %{HTTP_HOST} ^somedomain\.com$ [NC]
RewriteRule ^(.*)$ http://www.somedomain.com/$1 [R=301,L]

RewriteBase /
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /index.html(.*)\ HTTP/ [NC]
RewriteRule .* http://www.somedomain.com/ [R=301,L]