Is it possible to add a symbol on the map showing the location of a disabled parking place?
Do you want to map it?
Then read http://wiki.openstreetmap.org/wiki/Tag:amenity%3Dparking or look at the tag amenity=parking_spaces.
If you want just to see a symbol then look at e.g. http://www.rollstuhlkarte.ch
I would like to see this on openstreetmap.org.
This map is the basis for many other urban maps online.
It is very strange that there is not yet a suitable symbol for this place in the parking areas.
osm.org can’t display everything and will not do in future.
There are a lot of specialized maps which can do that for one topic.