DVD Titles with Jukebox

Not sure if this is the right forum. Please move if so.

I have a sony 301 dvd jukebox changer, and occasionaly certain dvd’s will automatically enter their title without me having to type it in. Where is this information stored? I know it’s not the Jacket_P folder because that only holds image files and many of my dvd’s that had title info didn’t have jacket_p folders. It’s also not the DVD volume label. Any help would be apreciated.
-Ed

spath will have a look at this from early next week