401.2. A registered decklist must have a complete, unambiguous record of the player’s Champion Legend, battlefields, Main Deck including Chosen Champion, Rune Deck, and sideboard (if applicable to the format).
401.3. Once a decklist has been registered and delivered to a competition official, it can’t be changed.
401.4. In a constructed event, a player’s deck must be registered prior to the start of the first round of competition.