&reftitle.runtime; &extension.runtime; Name Default Changeable define_syslog_variables "0" PHP_INI_ALL For further details and definition of the PHP_INI_* constants see ini_set. &ini.descriptions.title; define_syslog_variables boolean Whether or not to define the various syslog variables (e.g. $LOG_PID, $LOG_CRON, etc.). Turning it off is a good idea performance-wise. At runtime, you can define these variables by calling define_syslog_variables.