"Watched" commentaries

I've often wished there was a way to mark a DVD (or Blu-ray or HD-DVD or LaserDisc) commentary as "Watched" -- is that possible?

The best way would just be to tag it with something e.g. 'commentarywatched'

Yeah, that would work. But sometimes there are multiple commentaries and it's nice to know the participants.
Also, couldn't the tag editor have an auto-complete function? So that as I type "commentarywatched" (on the 3rd or 4th letter) it fills in the rest. I'm so used to Google Reader's auto-complete function when typing tags.
Also, couldn't the tag editor have an auto-complete function? So that as I type "commentarywatched" (on the 3rd or 4th letter) it fills in the rest. I'm so used to Google Reader's auto-complete function when typing tags.