[syslog-ng]sylog-ng internal messages

[Guillaume LACHENAL]

Where are syslog-ng internal() logged ?

using 
destination d_hosts { file( "/var/log/$HOST/$YEAR/$MONTH/$DAY/$FACILITY" );  };

i can't find anything relating to syslog-ng when grep'ing from 
/var/log/*/*/*/*/*

thanks for help

regards

Guillaume