Why are some cards not counted in the weighting of a set?
Recently I have added numerous cards to one of my sets and nearly all of them are indicating that the card is optional and not counted in the set weighting. Some don't make any sense. Like an Xfractor of one card is allowed while the Refractor is not counted. How does PSA determine whether a card will or will not be counted in the weighting? Is it possible that these cards were marked like that in error?