# File lib/mime/types.rb, line 237
    def docs=(d)
      if d
        a = d.scan(%r{use-instead:#{MEDIA_TYPE_RE}})

        if a.empty?
          @use_instead = nil
        else
          @use_instead = a.map { |el| "#{el[0]}/#{el[1]}" }
        end
      end
      @docs = d
    end