This is place for switch AUTH in admin/categories.php file ...
$access_field_array = array(
"auth_viewcat" => AUTH_ALL,
"auth_viewimage" => AUTH_ALL,
"auth_download" => AUTH_USER,
"auth_upload" => AUTH_USER,
"auth_directupload" => AUTH_ADMIN,
"auth_vote" => AUTH_ALL,
"auth_sendpostcard" => AUTH_ALL,
"auth_readcomment" => AUTH_ALL,
"auth_postcomment" => AUTH_USER
);
For lang for level - right after:
$access_array = array(
AUTH_ALL => $lang['all'],
AUTH_USER => $lang['userlevel_registered'],
AUTH_ACL => $lang['private'],
AUTH_ADMIN => $lang['userlevel_admin']
);