code: def process_param(self):
          
          self.log_response_message('got RETURNVALUE message')
          r = self._reader
          if tds_base.IS_TDS72_PLUS(self):
              ordinal = r.get_usmallint()
          else:
              r.get_usmallint()  # ignore size
              ordinal = self._out_params_indexes[self.return_value_index]
          name = r.read_ucs2(r.get_byte())
          r.get_byte()  # 1 - OUTPUT of sp, 2 - result of udf
          param = tds_base.Column()
          param.column_name = name
          self.get_type_info(param)
          param.value = param.serializer.read(r)
          self.output_params[ordinal] = param
          self.return_value_index += 1
docs: Reads and processes RETURNVALUE stream.
  
          This stream is used to send OUTPUT parameters from RPC to client.
          Stream format url: http://msdn.microsoft.com/en-us/library/dd303881.aspx