This file, USERS.LST, is the list of email addresses that the list-server mailing list uses to address the mail it sends to this list. This file is updated automatically when someone subscribes or unsubscribes to this list. It is a text file with one address per line ending in a carriage return/line feed.
You can edit this file using a text editor to add or delete addresses that will receive mail from this list. However, you must also edit the "Users" file (USERS.TXT) if you want people who use the "list" command to see an updated list of subscribers.
Note that this list will ignore any invalid addresses in this file (if, for example, you make a typing error while editing this file).