Grey brackets framing a bar? What is it?

Hi! I sent this file to a friend who is new to dorico, and when it came back these gray brackets are framing part of one bar. Does anyone know what its called, and what its for? I have tried to search for it, but its tricky when I dont know what it is. (and the friend doesnt know how she created them either).

Cycle locators. You can toggle their display under View β†’ Cycle locators

Ah okay! Thank you!