text: Im not sure how these grouped features work in OSM (and I've not been an active editor for a few years), but want to highlight with this station (hackney downs) being a "way" it is not picked up by the "overpass-api" when searching for "railway=station" 
  for example run the following query (node(around:2500,51.54802,-0.06098)[railway=station];
  out;) through http://overpass-turbo.eu/#  to see some stations are not found.
  