For various rate tables, the rate group instruction pat can be automatically established in the PAT manual. According to the existing flight segment information of PNR, the applicable freight rate can be automatically found from the database and added, and then the reference fare group FN, fare calculation group FC and payment method group FP are given. Pat's four manuals are the user manual of the air ticket inquiry interface and the air ticket real-time inquiry and reservation system. I. Basic introduction of inquiry system. The essence of its operation is based on online booking. At the same time, the online booking system submits relevant data to the airline letter system to obtain the PNR booking code.