Final answer:
To add a Frequent Traveler Number to a PNR, one would input a special code and the number into the airline reservation system, which varies by system but typically follows a format like FFNAirlineCode/TravelerNumber.
Step-by-step explanation:
The path to add a Frequent Traveler Number to a Passenger Name Record (PNR) in a reservation system varies depending on the specific system being used. Typically, travel agents or airline staff would enter a special code in the PNR's airline reservation system, followed by the frequent traveler number. This is usually done at the time of booking or can be added later into the passenger's record. The exact format can differ between systems, but often looks something like this:
FFNAirlineCode/TravelerNumber For example, if the airline code is UA (for United Airlines) and the traveler's frequent flyer number is 12345678, the entry in the PNR would be: FFNUA/12345678Always ensure the frequent traveler number is associated with the airline that is part of the reservation to ensure proper mileage credit and benefits.