To identify the interline carrier and relevant data
Standard Carrier Alpha Code
MS301 is the Standard Carrier Alpha Code (SCAC) of the interline carrier.
Code describing the relationship of a carrier to a specific shipment movement
Free-form text for city name
MS303 is the city where the interline was performed.
Code specifying the method or type of transportation for the shipment
Code (Standard State/Province) as defined by appropriate government agency