What is --log-file-appender flat

I see the following in the Logging docs:

--log-file-appender=flat|rolling|off

  configures if and how logging to a file should be done.
  The rolling appender will roll the files
  according to the defined date-time pattern.

--log-file-rolling-history=12

  configures the number of historical files to keep
  when using the rolling appender.

--log-file-rolling-pattern=YYYY-mm-dd
  
  configures the rolling file suffix
  (and therefore the frequency)
  of how files should be rolled.

--log-truncate

  configures whether the log file
  should be truncated on startup.

Does --log-file-appender off mean that files are overwritten instead of appended to? Is that different than --log-truncate? What is --log-file-appender=flat ?

I experimented with these options. Here is what I have inferred:

• --log-file-appender

  • rolling is the default. It renames the current log file, as needed, based on the date pattern.
  • flat disables the rolling feature. Log files are simply appended to. The rolling history and rolling patterns parameters are ignored.
  • off disables writing to log files altogether.

• --log-truncate

  • is only applicable with –log-file-appender flat option
  • replaces any existing log file at startup.

Double-check me on this and let me know if I’ve missed something.