/**
* Show a form for filtering namespace and username
*
- * @param string $par
- * @return string
+ * @param string|null $par
*/
public function execute( $par ) {
$this->setHeaders();
$this->outputHeader();
$this->getOutput()->addModuleStyles( 'mediawiki.special' );
+ $this->addHelpLink( 'Help:Diff' );
$form = HTMLForm::factory( 'ooui', [
'Page1' => [