A Reservation Code is a six-character, alphabetical code found on your itinerary. Airlines may ask for this code when you check in at the airport counter or kiosk.
A Trip ID is a 12-digit numeric code that may be found on your itinerary.
The Link a Booking feature is only available for reservations made through Sabre-affiliated travel agencies and airlines and other partners. Trips that are not booked through Sabre affiliates should be added to TripCase by forwarding the confirmation email to firstname.lastname@example.org, or by manually adding reservation details.
To know how to link reservation codes to your account, click here (bottom).