Hot tip in the US. In an elevator the floor with the star is the ground floor, regardless of what number is present.
This helps clarify any confusion between systems and also is clear for locations that have floors below the ground floor (I've most commonly seen this with parking structures)
I've seen multiple hospitals where the floor with the main entrance is 2, those will get the star. So it's more of a "here's how you leave" indicator rather than ground specifically
Yes, that's a good example I've seen too. So was the 2 not the ground floor?
I guess I've also seen places where the terrain is not even, so there are multiple entrances on different levels. I didn't take notice of what the elevators said though.