+ 'prefetch' => 1, // prefetch causes it to be cached in config settings. Usually this is a transitional setting. Some things like urls are permanent. Remove this comment if you have assessed & it should be permanent
+ 'config_only' => 1, //@todo - see https://wiki.civicrm.org/confluence/display/CRMDOC/Settings+Reference#SettingsReference-Convertingaconfigobjecttoasetting on removing this deprecated value