dgnuse files, what do they do and what are they for?

Good Morning,

I was asked a question "What do dgnuse.log files do, and what are they for?" and I really couldn't answer it.  All I could do was hazard a guess that the dgnuse.log file records when a dgn has been saved, not necessarily edited but 'saved'.  I tried googling it but I didn't come up with anything.  Anyone have more insight, or where I can find information about them?

Thank you have a good weekend,