I have been looking at the ESI (Edge-Side-Includes) specs, but I cannot quite figure out how esi:inline elements work. Can anyone explain that?
Finally, I figured it out. You send a response with an <esi:include> and in the reply to that one you include <esi:inline>-marked fragments for later re-use.
That is a pretty slick way to allow retrieval of many small pieces in one large request.