Since some time, there are tons of unnecessary POI symbols in many cities sitting on every ordinary residental building. These POIs supersede the also the street numbers.
How to switch that POI off in the Map Explorer? The reason might be the tag: building=apartments.
In some parking areas, there are many parking symbols displayed. For example, at the coordinates 50.8551722, 12.7847316, someone added many small areas. Each area represents 1 car. I think the person wanted to know how many cars can park there.
Thank you, turning off the POIs is working. At least for this special case, this solutions seems to be viable. Regarding the inflatory marking of parking spots, it is more difficult.