I'm up in the Air

If you look out your plane window, and see labels on the wing, written in what appears to be Brother P-Touch, is that bad?

This one on the right says "Boost Pump" -- good to know. I wondered where I'd left that thing.


Conversely, the one to the left says "No Step Aft", and has a line that one can only assume you should not step aft of. All good, but if you were not supposed to, oh, step aft of a particular line on a 737 wing, wouldn't you want the label to be a skosh more permanent?