The funny thing about Gatherer is that if you use the website, it tells you that it is better in the app. However, it won't show any DFCs/Transform cards or adventures, and is generally more irritating. I can see why you were confused, if you ever notice some card that is apparently "legal" and has mechanics like Conjure, Perpetually, Seek, or Draft a card from [Cardname's]
spellbook, be wary.