An ExtensionModule is a collection of optional data that may be used to extend the core WellFormedEntry model.
Extension modules have a UniqueIdentifier and a DefinedDataModel. AnswerMe: PLEASE HELP DEFINE THESE.
+1. What is the SyntaxExtensionMechanism?
Is this still part of the (future) standard?
I think extension modules of some sort are key. For instance, in the context of wikis, we'd like to extend the feed format to add things like the importance (major/minor) of each change. This has already been done with RSS (see RssForWikis).