Facilities

While the full list of facilities is reproduced here for completeness, using anything but LOG_AUTH, LOG_AUTHPRIV, and/or LOG_LOCAL0..7 is unlikely to have the desired results.

Facility Description

LOG_AUTH

security/authorization messages (use LOG_AUTHPRIV instead in systems where that constant is defined)

LOG_AUTHPRIV

security/authorization messages (private)

LOG_CRON

clock daemon (cron and at)

LOG_DAEMON

other system daemons

LOG_KERN

kernel messages

LOG_LOCAL0…7

reserved for local use, these are not available in Windows

LOG_LPR

line printer subsystem

LOG_MAIL

mail subsystem

LOG_NEWS

USENET news subsystem

LOG_SYSLOG

messages generated internally by syslogd

LOG_USER

generic user-level messages

LOG_UUCP

UUCP subsystem

Logfiles

OS Level LOG_AUTH LOG_AUTHPRIV LOG_USER
CentOS 7     /var/log/secure  
FeeBSD INFO /var/log/auth/log /var/log/auth/log
NOTICE /var/log/auth/log /var/log/auth/log /var/log/messages
Ubuntu 18 (all) /var/log/auth.log /var/log/auth.log /var/log/syslog