public static function clearAfter($what)
    {
        $cache = new static;

        switch ($what) {
            case 'userDelete':
                $cache->delete('forum.latestposts');
                // no break
            case 'activate':
                $cache->delete('members.fieldlist');
                $cache->delete('forum.memberscount');
                break;
            case 'categoryDelete':
            case 'forumDelete':
            case 'threadDelete':
            case 'postDelete':
                $cache->delete('forum.threadscount');
                $cache->delete('forum.postscount');
                $cache->delete('user.threadscount');
                $cache->delete('user.postscount');
                $cache->delete('forum.latestposts');
                break;
            case 'threadMove':
            case 'postMove':
                $cache->delete('forum.threadscount');
                $cache->delete('forum.postscount');
                $cache->delete('forum.latestposts');
                break;
            case 'newThread':
                $cache->delete('forum.threadscount');
                $cache->deleteElement('user.threadscount', User::loggedId());
                // no break
            case 'newPost':
                $cache->delete('forum.postscount');
                $cache->delete('forum.latestposts');
                $cache->deleteElement('user.postscount', User::loggedId());
                break;
        }
    }