When playing Stack the Deck (1 cost purple spell), do you reveal the card you add to your hand to your opponent?

Ruling: You do not reveal the card you add to your hand unless the card text specifically states you must reveal it.

Nuances:

• In TCGs generally, you reveal cards moved from hidden zones only when your choice is restricted (to prove you're following restrictions)
• When you can choose any card, there's no need to reveal unless the card explicitly says to