In life we all have unwritten rules like how far behind someone you stand while you are in line or the “nod of recognition” you give someone if you make eye contact while they are walking toward you.
There are lots of these about airplanes, famously about 3-deep-seats.
But I’m curious about the unwritten rule for the window.
To me, if you are in the window seat, unless someone specifically needs the window to be open for motion sickness or something, you are responsible for closing the window once the plane is at cruising altitude so people can sleep if they need to. If you dont do that, I find it a little grating.
Curious what other folks think.
If it’s a sharpie, you can get rid of the mark with hand sanitizer.
That’s an old teacher trick. A better one is using a dry erase marker to remove permanent marker. Not perfect, but works in a pinch.