A tractor pulls a cargo tank combination with three separate cargo tanks, each built to a different specification and tested at different intervals. Under 49 CFR 180.415(c), how must their test/inspection markings be arranged?

49 CFR 180.415(c)

On a multi-tank combination, each compartment can have its own test schedule, so matching each marking to its tank's physical position (front to rear) is what lets an inspector correctly tell which test history belongs to which tank.