Every distinct wording since 2010, newest first.
April 14, 2023 · March of the Machine
Scheme cards remain in the command zone throughout the game, both while they’re part of a scheme deck and while they’re face up. They’re not permanents. They can’t be cast. If a scheme card would leave the command zone, it remains in the command zone.
July 23, 2021 · Adventures in the Forgotten Realms
At the start of a game, before decks are shuffled, each player may put any number of conspiracy cards from their sideboard into the command zone. Conspiracy cards with hidden agenda are put into the command zone face down. (See rule 702.106, “Hidden Agenda.”)