Malcolm, I think I’m going to implement the media type suffix change by adding an extra parsing step in media_type.clj and add a :suffix-type field to the MediaTypeMap record that is either nil (in the case of non-suffixed types) or a reference to another MediaTypeMap which is the suffix type. Then in body.clj the defmulti render-* will first check (keys methods render-*) for a matching :name, and if not found, a matching :name in a :suffix-type (if present). Thoughts?

That sounds a good approach to me