Which of the following is required for sideboarding?

In Magic: The Gathering tournaments, sideboarding is a crucial aspect that allows players to modify their decks between games in a match. The relevant rule regarding sideboarding states that players may use notes during this process, but they are not required to reveal those notes to their opponent. This allows players to reference strategies or card interactions without exposing specific information about their sideboarding choices.

Choosing to utilize brief notes can help players remember important details, but it's essential to clarify that this option is entirely at the player's discretion. The requirement is that players should know the contents of their sideboard and the main deck while being able to access any notes they may find helpful. This aligns with the nature of strategic play, where preparation and knowledge are key components without necessarily imposing additional requirements on players to disclose their strategies.

The other options presented do not accurately reflect the established requirements. For instance, players are not obligated to reveal their sideboard lists before starting since revealing deck information can impact strategy. There is also a set minimum limit of 15 cards for a sideboard in sanctioned play, which makes the notion of "no requirements" incorrect. Lastly, the submission of cheatsheets to a judge is unnecessary in the context of sideboarding, as it is not a requirement in regular