I'm not sure I know the answer to this question and thought the fine people on this board would have some good input.
By the way, I'm aware of 1996-97 Hockey and Basketball issues from Flair that had them (Blue Ice and I think Row 0 Showcase or something like that).
I'm not sure the 1996 Flair Baseball had those serial numbered parallels yet.
By the way, I'm thinking parallel only meaning identical card picture and maybe something different like color and a sequential serial numbered added to the card. I know Donruss had those /10,000 cards that were impossible to find in a pack unless you went to see them at a card show back in the day.
Thanks for reading and sharing any knowledge you've got!