Marking that entrance=staircase/main has no sign with code (in area where it is to be expected)

[dieterdreist (Martin Koppenhöfer)]

Might be nitpicking, but I’d say put ref=no at first, and if you (or anyone) find that ref does exists somewhere, add it and ref:signed=no. Start simple, assume that if not signed it probably doesn’t exists anywhere and expand when you know more.

ref=no is not suitable because it can be easily confused with ref=no