When List Fields start, it check the existence of the so-called Notes Backup Database. This database is a List Fields-created database which contains work documents and backups of documents which List Fields change. In other words, List Fields won't change a but unless it has a complete backup of documents involved.
If the database doesn't exist, List Fields will inform you about the creation of this database, and you will see this message:
The database is created with you (or more precisely, the user ID you run Notes in context of) as the only person with access to the database.