Who is on the chain crew, and who directs us?

In the rule book the chain crew are the "Downbox and Yardstick Officials", also called minor officials: one Downs Box Official and two Yardstick Officials (with an optional third Yardstick Official).

They act under the direction of the Down Judge, who supervises them in placing the distance chain and downs box under the direction of the Referee. The Referee has prime responsibility for the count of downs and for control of the downs box and distance chain, with the Down Judge assisting.

Source: Canadian Amateur Rule Book for Tackle Football 2026-2027, Rule 2, Sections 7 and 10, and Case Book comment 3-4-1.