OK, this extract works for 1.20 function JidanniOpenGraphMetaPageHook(&$out,&$sk){global $wgLogo; $out->addHeadItem("meta:property:og:image", Html::element('meta',array('property'=>'og:image','content'=>wfExpandUrl($wgLogo)))."\n");return true;} $wgHooks['BeforePageDisplay'][] = 'JidanniOpenGraphMetaPageHook';