Historical Rules · 7 August 2020
Rule 407.3
Official source text from the 7 August 2020 Rules release
A few cards have the text “Remove [this card] from your deck before playing if you’re not playing for ante.” These are the only cards that can add or remove cards from the ante zone or change a card’s owner. When not playing for ante, players can’t include these cards in their decks or sideboards, and these cards can’t be brought into the game from outside the game.