Oh, got it, it's that overlap. Okay, that makes it a mistake on my part, should have noticed it's crossing a part of the building that's not there (as in not on that level) physically.

You're right, there's an entrance for the restaurant, which technically is an entrance into the building, but not the office part. StreetComplete doesn't make this clear, I'll take more care next time when dealing with entrances, thanks!

An honest mistake on my part, thanks for spotting it.

Interesting, I didn't edit these tags directly, but via StreetComplete, so I guess this should be reported as a bug in their repo, if it produced incorrect tags.

Right, thanks for the help, I'll remember to check register adries as well next time.

They're not proper buildings, but rather a shipping container and a container house with fast food joints inside them. In addition to no number displayed (which in itself doesn't mean anything), they don't show up on cadastral maps, therefore they don't exist as buildings before the law. So they can't have numbers. There is a small chance that the cadastre has erroneous data, but I went with the assumption that they don't.

is this line of thought wrong?