The list is loaded, when the configuration file contains section [list_log]. The section may contain the key "file". If "file" is present, on loading list_log, the file is opened and a marker is inserted. On proper shut down, another marker is inserted. The modules send data to list_log and the latter fills the data to the file.
On the roadmap is to add ability to list_log to add data to syslog and journald.