freebeer
Hallo BearT,
Thanks for the explanation.
I have simply used the preset fields in my editor, thus my encouragement to correct my input.
The newly-created building is way
https://www.openstreetmap.org/way/530922338
and has the presumed-incorrect tag.

The entire extent of my changeset can be seen at
https://overpass-api.de/achavi/?changeset=52720642
although everything else is simply v1 additions of missing outlines around Ybbsitz/the Prochenberg and can safely be ignored for validation.
With the exception of renaming the Nothbergstr. to In der Noth, again based on basemap.at data, although no-name may also be applicable.
I hesitate to leave a variant of Nothbergstr. as I would expect it to at least have some mention found by g00gle outside of OSM (I mistakenly tagged a street in Houston Texas that only had one mention in a search, and that turned out to be false).
My printed tourist info for the area is not at hand to serve as a reference :-(

I hope my errors can be corrected without too much pain :-)
