Many airline travelers can confirm that bathrooms, or lavatories, are riddled with issues, like foul odors, wet floors, decreasing sizes, and even barefoot passengers. But then there's the dreaded ?class? system ? which requires passengers to use the lavatory in their ticketed cabin, be it first class or economy.

On most commercial flights, the general rule is that you should use the bathroom in your own ticketed cabin. If you are seated in Economy or Premium Economy, you are expected to use the lavatories located in the middle or rear of the aircraft. This is partly due to post-9/11 security regulations—especially on flights within or to the United States—which discourage passengers from congregating near the cockpit or crossing through the "curtain" into the premium cabin. Flight attendants often enforce this to ensure the privacy and lack of queues for passengers who have paid a significant premium for First or Business Class. However, in an emergency or if the other lavatories are blocked by a beverage cart, a flight attendant might grant permission to use the forward lavatory, but this is a courtesy rather than a right. On many international long-haul flights, the distinction is strictly maintained to preserve the "exclusive" atmosphere of the front cabin. It is always best to wait for the cart to pass or use the facilities at the back to avoid an awkward encounter with the crew.