-define(SD_EMERG,   "<0>"). % system is unusable
-define(SD_ALERT,   "<1>"). % action must be taken immediately
-define(SD_CRIT,    "<2>"). % critical conditions
-define(SD_ERR,     "<3>"). % error conditions
-define(SD_WARNING, "<4>"). % warning conditions
-define(SD_NOTICE,  "<5>"). % normal but significant condition
-define(SD_INFO,    "<6>"). % informational
-define(SD_DEBUG,   "<7>"). % debug-level messages