Rail carriers use this transaction set to communicate the removal or reduction of prescribed service requirements for rail cars, typically in response to operational changes, service agreement modifications, or changed transportation needs. Shippers and freight forwarders receive the 432 to understand which cars no longer operate under specific prescriptive constraints. The transaction centers on three key segments: the BGN (Beginning Segment) establishes the business purpose and context; the BLR (Transportation Carrier Identification) identifies which carrier is issuing the deprescription; and the CIC (Car Information Control) segment—which appears within the mandatory CIC Loop—specifies individual rail cars being deprescribed, with optional DRT (Deprescription Rate Detail) segments capturing the specific rate or service terms being removed or modified.

For example, Union Pacific Railroad sends a 432 transaction to Midwest Logistics Inc. to notify them that 47 refrigerated boxcars previously prescribed for temperature-controlled pharmaceutical shipments are no longer subject to that requirement due to seasonal demand reduction. Within the transaction, the BLR segment identifies Union Pacific as the carrier, while the CIC Loop repeats 47 times—once for each car—with each CIC segment containing the specific car number and the associated DRT segments detailing which temperature control specification or service tier is being removed. This allows Midwest Logistics to update their shipping protocols and redirect those cars to general freight uses without the previous service constraints.