About track labels

can someone tell what logic is followed by volumio for determining the track order and labels in a NAS directory?

After copying a cd or dvd I usually add a “cd.toc” file with the just the name of the files in the order that I want them. Usually this works, but not always.

For instance I now have a list of mp4 files, and I can not get rid of the label that is somewhere mentioned in the mp4s themselves…