There are three special variables that contain the names of all variable of the same group. This command specifies the location of an alternate log file to be used instead of the default system syslog facility. This command controls the amount and type of output written to the system syslog facility or the alternate logfile log file. By default, all output is turned on. Within these classes four types of messages can be controlled.
Statistical output is controlled with the statistics keyword.
The final message group is the status messages. This describes mainly the synchronizations status. Configuration keywords are formed by concatenating the message class with the event class. The all prefix can be used instead of a message class. This would just list the synchronizations state of ntpd and the major system events.