Hello Hungarian mappers!
There is a single neighborhood in Budapest which now has almost all of the deprecated addr:staircase tags in the OSM database, here https://overpass-turbo.eu/s/t6N
In Finland addr:staircase was replaced by addr:unit, which matches the Finnish addressing system very well. In this case though, the entrances in the buildings in question have both unique addr:housenumbers and addr:staircases. Is the staircase letter part of the official address, so it could be perhaps replaced with addr:unit, or should the tag be ref=*, or something else?
I hope someone in the Hungarian OSM community could have a look.