MediaWiki:Common.css

/** CSS placed here will be applied to all skins */
#f-poweredbyico { display: none; }

/* http://www.mediawiki.org/wiki/Manual:FAQ#How_do_I_remove_the_article.2Fedit_etc_tabs.3F */
/*
li#ca-edit,
li#pt-preferences,
li#pt-logout,
*/
li#ca-nstab-main,
li#ca-talk,
li#ca-viewsource,
li#ca-history,
li#ca-delete,
li#ca-move,
li#ca-protect,
li#ca-watch,
li#ca-unwatch,
li#pt-userpage,
li#pt-mytalk,
li#pt-watchlist,
li#pt-mycontris        /* not a typo */
    { display: none; }