Ocassionally I'll open some packs and get a preview card for a different set than the pack I'm opening. I'm just curious, why are those preview cards listed on the set that they're previewing instead of the set that the card was pulled from? Not a big deal, and I'm sure there's a logical reason why it's done that way, but sometimes it can be hard to track down the proper card in the database to add to my collection. I'm assuming that it's done that way because those particular preview cards could be inserted into several different sets, and rather than have the same card cataloged multiple times, it just gets put on the set featured on the preview card.
Hopefully that's not too terribly confusing lol, but if anyone knows any other reasons why that's done, let me know. More specifically, I'm referring to some of the early 90's Classic Draft, Best, 4 Sport, Images, NFL Experience, etc.