It is the VBI data. Some players can eliminate it. You shouldn't see it on your TV.
Is VBI used on DVDs? I thought they had their own method of carrying data, with the text etc. superimposed over the image. Also, the video isn't NTSC or other, until the data is used to create the video signal. VBI is part of analog video signals only and should not be present on digital signal (digital signals have no need for blanking intervals). However, there may be other garbage at the top of the screen that has nothing to do with VBI.The white line at the top of the screen is VBI information