Historical Rules · 14 June 2019
Rule 201.3b
Official source text from the 14 June 2019 Rules release
If a player wants to choose the name of a split card, the player must choose the name of one of its halves, but not both. (See rule 708.) If a player is instructed to choose a card name with certain characteristics, use only that half’s characteristics to determine if this name can be chosen.