My upstairs neighbour, Kathy, has a sign by her door:

"Please remove footwear here please

Thanks"

Ignore the extra please for now. Let's focus on the word footwear; it seems to imply that she wants her guests to take off things other than shoes or boots. Socks? Geez, if that's the case, I'd hope for her guests' sake that her floor is clean. What if guests have rings on their toes? She'd damn well better have something to keep the rings in, if she's that picky. Or perhaps she means cleats. Good call; cleats would mark up her floor.

So yeah, I'm thinking that she must be frequented by people who wear things on their feet other than shoes or boots. Skiis? This is where I draw the line. If someone trudged all the way up her stairs while wearing skiis, they deserve a special treat--like being allowed to keep the skiis on inside.