Every distinct wording since 2010, newest first.
April 14, 2023 · March of the Machine
If an effect allows a player to cast a double-faced card as a face-down creature spell, or if a double-faced card enters the battlefield face down, it will have the characteristics given to it by the rule or effect that caused it to be face down. That card remains hidden, using a face-down substitute card (see rule 713) and/or opaque sleeves. See rule 708, “Face-Down Spells and Permanents.”
July 23, 2021 · Adventures in the Forgotten Realms
If an effect instructs a player to choose a card name, the player may name either face of a double-faced card but not both.