Documentation by Jie CAI.

3.3. Extension mechanism of MLP

The MLP has been designed with extensibility from the beginning. To achieve the extension mechanism, there are several design principles:

  1. Separate DTDs for definitions that are common to all messages, so they can be re-used
  2. Use a message extension mechanism to add new messages. An extension DTD must be created, and contain another entity parameter. Then in order to use it, the extension DTD has to be explicitly referenced in the XML document (messages).
  3. Use a parameter extension mechanism to add new parameters to existing messages. The method is the same with the message extension mechanism. The parameter is different.