Rham's Readings says:
Controller Noon, Boot: Reveal the top card of an opponent's deck. If that has the same value or suit as the top card in their discard pile, gain 1 ghost rock. If a joker is revealed, ace it and reveal the next card.
I've had at least one opponent assume mid-game that the revealed card is discarded...but looking at the test, there's 0 reason to assume that.
Talking to @Lapp on the Discord channel, he mentioned that the revealed card was supposed to be discarded.
Is there an official ruling/errata that I can point to?