Z.3.1- The graveyard is where cards go when they are discarded from a player's hand, when they are destroyed or sacrificed while in play, or when they are countered while being played as spells. [CompRules 1999/04/23]
Z.3.2- The graveyard is also called the discard pile. [CompRules 1999/04/23]
Z.3.3- The graveyard has an order to it. All cards that enter the graveyard are placed on top of it. [CompRules 1999/04/23] Because of this and Rule Z.1.4, if more than one card is to be placed in at a time, the owner of that graveyard decides the order those cards get stacked in. [CompRules 1999/04/23]
Z.3.4- Neither player may change the order of any graveyard. [CompRules 1999/04/23]
Z.3.5- Information about the graveyard is public. All players have the right to know what cards are in every player's graveyard and what order they are in. [CompRules 1999/04/23]
Z.3.6- Abilities of cards in the graveyard cannot be used and have no effect on the game unless the card specifically says they do. For example, the Nether Shadow has an ability which can be played while it is in the graveyard, but the White Knight does not have Protection from Black while in the graveyard. See Rule A.1.3. [CompRules 1999/04/23]
Z.3.Ruling.1- Any token sent to the graveyard ceases to exist. This is a state-based effect (see Rule T.11), so it is not possible to announce a spell or ability to affect the token before it is gone. See Rule K.25.6. [CompRules 1999/04/23]
Z.3.Ruling.2- Cards in the graveyard are just cards. They have no memory of whether they were ever in play or not, or of anything that may have happened to them when they were in play. This includes removal of any choices about the card, any alterations via spells like Magical Hack, any counters on the card, and so on. [D'Angelo 1999/05/01] See Rule Z.1.3.
Z.3.Ruling.3- If something goes to the graveyard then comes back, it is considered a new card since it forgot its past when it went to the graveyard. [bethmo 1994/05/03] See Rule Z.1.3.
Note- Each player starts the game with an empty Graveyard. [CompRules 1999/04/23]
Note- When a card is brought from the graveyard directly into play, see Rule G.28.