Historical Rules · 14 April 2023
Rule 702.158c
Official source text from the 14 April 2023 Rules release
Any time a permanent with space sculptor and any creatures without a sector designation are on the battlefield at the same time, each player who controls one or more of those creatures and doesn’t control a permanent with space sculptor chooses a sector designation for each of those creatures they control. Then, each other player who controls one or more of those creatures chooses a sector designation for each of those creatures they control. This is a state-based action (see rule 704.5u).