According to http://www.rsyslog.com/doc/rsyslog_conf_actions.html:
You may prefix each entry with the minus "-'' sign to omit syncing the file after every logging.
news.crit /var/log/news/news.crit news.err /var/log/news/news.err news.notice -/var/log/news/news.notice
Таким образом, документы указывают:
Различные возможные действия:
Но ничего не упоминает о префиксе -
According to http://www.rsyslog.com/doc/rsyslog_conf_actions.html:
You may prefix each entry with the minus "-'' sign to omit syncing the file after every logging.