What are the rules of saying UNO?

What are the rules of saying UNO? The Rule of Calling “UNO”When a player is about to play to his/her second to last card, they have to announce it by saying “UNO”. If a player does not call UNO, and another player notices before the next person plays, the offending player must pick up 4 cards from the draw pile.

The Rule of Calling “UNO”

When a player is about to play to his/her second to last card, they have to announce it by saying “UNO”. If a player does not call UNO, and another player notices before the next person plays, the offending player must pick up 4 cards from the draw pile.