Translations:Optional settings/3/en
From LimeSurvey Manual
These optional settings can only be found in the file /application/config/config-defaults.php of a standard installation - some of them are only used for first installation and overriden in Global settings.
If you want to change these settings please do not change it in config-defaults.php but copy the particular setting/line over to /application/config/config.php in 'config'=>array() and change it there.
All settings in config.php overwrite the default values from config-defaults.php and some of these settings get overridden in the Global settings dialog (New in 1.87 ) . This way it is much easier to upgrade your installation at a later time!