Thus sites which host MWS limited tournaments make players build their decks online, and use a security code which will change with any contents of the deck. This precaution helps prevent any dishonest play in a limited game, so long as both players ensure that their opponent's code is valid.
As a result, sites hosting MWS limited tournaments allow players to create their decks digitally and employ a changing security code tied to the deck's contents. This safeguards against dishonesty in limited games, assuming both participants validate their opponent's code.