The 72-hour rule frequently referenced in airline industry operations pertains to stringent ticket modification, cancellation, and rebooking windows managed by international carriers. For Qantas, this generally dictates that travelers must finalize booking changes, submit refund applications, or address specific fare-class adjustments at least 72 hours before the scheduled flight departure time to avoid significant financial penalties or administrative fees. This policy is designed to allow the airline sufficient time to maximize seat inventory management, confirm catering requirements, and ensure accurate passenger manifesting for long-haul flights. Travelers are strictly advised to consult the specific fare conditions attached to their electronic ticket receipts for exact deadline accuracy.