text: It seems that boundary=land_area was discussed at german talk-de, but 
  
  1. type=land_area was used at http://wiki.openstreetmap.org/wiki/Relation:land_area
  2. land_area=administrative was mentioned at http://wiki.openstreetmap.org/wiki/Relation:boundary
  
  We need better explanation at wiki: 1. what is tagged and 2. according to whom/what (sources) and 3. tagging approach