Article continues below advertisementAt airport gates around the world, a small but consequential drama plays out daily: passengers arguing over whether a bag qualifies as a carry-on or a personal item. For travelers squeezed by tightening airline policies, this distinction can mean avoiding an unexpected fee, a forced gate check, or simply being able to keep one's belongings nearby. As airlines increasingly monetize every inch of space, travelers face a shift in definitions - one that has quietly transformed cabin baggage into a contested frontier.