Log Settings is where you are able to enable or disable logging of partyline and gameline chat. After clicking on Misc. Settings at the bottom of the program, simply left click on the words Log Settings on the left side of the program, as seen here:
After doing so, you should see options similar to the following:
To enable or disable logging, simply check or uncheck the checkbox marked Log PartyLine/GameLine to File accordingly.
Beneath that is an option to select what directory you wish to save log files to. To change the log directory, simply left click in the edit space. This will bring up a browse dialog that you can use to browse and set logging to a different directory.
Log files are saved as server-ip.log, where server-ip is the host/ip specified under the Client Settings area. If you are the server, the log file will be saved as localhost.log. Log files are saved in text format, so you may view them in your favorite text editor, such as notepad.