MDG Add-Ins are specialized types of Add-In that have additional features and extra requirements, for Add-In authors who want to contribute to Enterprise Architect's goal of Model Driven Generation.
One of the additional responsibilities of an MDG Add-In is to take ownership of a branch of an Enterprise Architect model, which is done through the MDG_Connect event. Unlike general Add-In events, MDG Add-In events are only sent to the Add-In that has taken ownership of an Enterprise Architect model branch on a particular workstation.
MDG Add-Ins identify themselves as such during EA_Connect by returning the string 'MDG'.
Unlike ordinary Add-Ins, responding to MDG Add-In events is not optional, and methods must be published for each of the MDG Events.