Pagina principale

var isMainPage = (document.title.substr(0, document.title.lastIndexOf(" - ")) == "Main Page"); var isDiff = (document.location.search &&

                (document.location.search.indexOf("diff=") != -1 ||
                    document.location.search.indexOf("oldid=") != -1
                )
            );

if (isMainPage && !isDiff) {

   document.write('<style type="text/css">/*<![CDATA[*/ h1.firstHeading { display: none !important; } /*]]>*/</style>');

}

Test