Syslog messages--as standardized in RFC3164--embed a priority number (the PRI part) which is composed of a severity and a facility value. The constants which encode these values are specified in section 4.1.1, and are made available by this module. For instance, the exportable LOG_FTP constant has a value of 11, the value for the FTP facility. WWW: http://search.cpan.org/dist/Log-Syslog-Constants/