Forgot to add the description in the hashtags:
"Added, adjusted and squared buildings; Separated two buildings glued together by two nodes; #hotdqi2021

Hello :) There was a way which contains these three tags and was located at the same position as another way with the building=yes tag. This is also the case with the other buildings with these 3 tags, the only difference is the osm_id. The source of this information was the OSM user named sherryaine and she added them last May 28, 2019. I'm not sure, but I think the code is for the postal code and the fclass=building should be building=yes. I transferred these 3 tags to the way with the building tag, so that there would no longer be duplicated ways.