RE: Track "id" format?

> I'm concerned about having id clashes. If the page contains a out-of-band track that has an id that matches the one we generate we could have problems. Both the in-band and out-of-band text tracks would have the same id.

I'm not sure there's any way we can prevent this. It seems to me that we should:

  *   Define what happens when the id on an in-band text track is the same as the id on an out-of-band text track, with media fragments and getTrackById(). I'd recommend that the out-of-band track is used, since that's probably what the author is expecting. Luckily, this situation can't happen with audo and video tracks (yet?).
  *   Recommend that people use ids that are unlikely to conflict (not numbers).