module RDF
  class PTR < Vocabulary("http://www.w3.org/2009/pointers#"); end
  class RDFA < Vocabulary("http://www.w3.org/ns/rdfa#"); end
  class XML < Vocabulary("http://www.w3.org/XML/1998/namespace"); end
  class XSI < Vocabulary("http://www.w3.org/2001/XMLSchema-instance"); end
end