No, you cannot stack numbers in Uno.
No, you cannot stack colors in Uno.
No, in Uno, you are not allowed to stack cards.
No, you cannot stack reverse cards in Uno.
No, in Uno Flip, you cannot stack cards or add 5 to the stack.
No, in Uno, you cannot stack cards of the same number.
No, in Uno, you cannot stack draw 4 cards.
No, in Uno you can only stack two cards at a time.
No, in Uno you cannot stack the same number on top of each other.
No, you cannot stack a Draw 4 on a Draw 2 in Uno.
Yes, in Uno, you can stack cards to change the direction of play.
No, you cannot stack a 2 card on top of a 4 card in the game of Uno.
No, you cannot stack a Skip card on top of another Skip card in Uno.