Manual:Redirects

A redirect is a page that contains a line such as:

Redirects are recorded in the redirect table. Configuration settings relevant to redirects include:
 * $wgDebugRedirects (defaults to false), displays redirect location instead of actually redirecting to the target URL.
 * $wgDisableHardRedirects (defaults to false), disables redirects to special pages and interwiki redirects, which use a 302 and have no "redirected from" link.
 * $wgInvalidRedirectTargets (defaults to ) is an array of invalid page redirect targets.
 * $wgMaxRedirectLinksRetrieved (defaults to 500), is the maximum number of links to a redirect page listed on Special:Whatlinkshere/RedirectDestination.
 * $wgMaxRedirects (defaults to 1), is the max number of redirects to follow when resolving redirects.
 * $wgRedirectSources (defaults to false), is a regular expression to restrict URLs which will be displayed as 'redirected from' links.

Double redirects
There are several ways to fix double redirects. fixDoubleRedirects.php is a maintenance script that fulfils that purpose. $wgFixDoubleRedirects is a configuration setting that can take care of such redirects as they are created, but it is only suitable for use on a private wiki because page move vandalism causes problems when it is set to.