This allows alternate ways to enable debugging. NONE means no alternate methods are allowed. URL means when the keyword SMARTY_DEBUG is found in the QUERY_STRING, debugging is enabled for that invocation of the script. If $debugging is &true;, this value is ignored. debugging = false; // the default $smarty->debugging_ctrl = ($_SERVER['SERVER_NAME'] == 'localhost') ? 'URL' : 'NONE'; ?> ]]> See also debugging console section and $debugging.