comprensione url

[tatored]

http://www/wiki/index.php?title=Spec...fiche&feed=rss

ciao vorrei capire dal ? in poi la funzione del ":" in questo url ...che fa riferimento a questa pagina php:

# Initialise common code
$preIP = dirname( __FILE__ );
require_once( "$preIP/includes/WebStart.php" );

# Initialize MediaWiki base class
require_once( "$preIP/includes/Wiki.php" );
$mediaWiki = new MediaWiki();

wfProfileIn( 'main-misc-setup' );
OutputPage::setEncodings(); # Not really used yet

$maxLag = $wgRequest->getVal( 'maxlag' );
if ( !is_null( $maxLag ) ) {
    if ( !$mediaWiki->checkMaxLag( $maxLag ) ) {
        exit;
    }
}

# Query string fields
$action = $wgRequest->getVal( 'action', 'view' );
$title = $wgRequest->getVal( 'title' );

$wgTitle = $mediaWiki->checkInitialQueries( $title, $action );
if ($wgTitle == NULL) {
    unset( $wgTitle );
}

wfProfileOut( 'main-misc-setup' );

#
# Send Ajax requests to the Ajax dispatcher.
#
if ( $wgUseAjax && $action == 'ajax' ) {
    require_once( $IP . '/includes/AjaxDispatcher.php' );

    $dispatcher = new AjaxDispatcher();
    $dispatcher->performAction();
    $mediaWiki->restInPeace();
    exit;
}

# Setting global variables in mediaWiki
$mediaWiki->setVal( 'action', $action );
$mediaWiki->setVal( 'CommandLineMode', $wgCommandLineMode );
$mediaWiki->setVal( 'DisabledActions', $wgDisabledActions );
$mediaWiki->setVal( 'DisableHardRedirects', $wgDisableHardRedirects );
$mediaWiki->setVal( 'DisableInternalSearch', $wgDisableInternalSearch );
$mediaWiki->setVal( 'EnableCreativeCommonsRdf', $wgEnableCreativeCommonsRdf );
$mediaWiki->setVal( 'EnableDublinCoreRdf', $wgEnableDublinCoreRdf );
$mediaWiki->setVal( 'JobRunRate', $wgJobRunRate );
$mediaWiki->setVal( 'Server', $wgServer );
$mediaWiki->setVal( 'SquidMaxage', $wgSquidMaxage );
$mediaWiki->setVal( 'UseExternalEditor', $wgUseExternalEditor );
$mediaWiki->setVal( 'UsePathInfo', $wgUsePathInfo );

$mediaWiki->initialize( $wgTitle, $wgArticle, $wgOut, $wgUser, $wgRequest );
$mediaWiki->finalCleanup ( $wgDeferredUpdateList, $wgOut );

# Not sure when $wgPostCommitUpdateList gets set, so I keep this separate from finalCleanup
$mediaWiki->doUpdates( $wgPostCommitUpdateList );

$mediaWiki->restInPeace();