text: There are a few "disused:railway=abandoned" here, such as http://www.openstreetmap.org/way/234864091/history .  What exactly are they?
  
  A railway=disused is normally "still visible on the ground, rails intact"; railway=abandoned is normally "still visible on the ground, rails gone"; the "disused" prefix normally means (on e.g. an amenity or shop) that the physical thing is still there but no longer does the original purpose. 
  
  See comment on http://www.openstreetmap.org/changeset/33714018
  