Question about XIFF's event and data packages?

Should a developer use the classes in XIFF’s event and data packages? Or are those used mostly internally in XIFF? The reason why I ask, I am using PureMVC as an application framework and would like to implement them if they are designed to be implement by a developer. If not, then I would like to use the typical value-objects and enums that you would find in a PureMVC project.

Thanks.