Mark Nottingham:
In an ideal world, yes. However, many aggregators I've seen will highlight or otherwise draw attention to entries that have changed, using various metrics for 'change' -- including, I suspect, the introduction of new child elements. YMMV, of course.
For me at least, the key issue is whether the atom:updated time has changed (what RFC4287 considers a significant update). However there would have to be a content change too (replacing the content with "this entry has been deleted" would do it). New child elements wouldn't make any difference.
Has anyone done a survey of how aggregators behave under different conditions like this?
Well there's the "Updated Conformance Test" on the Atom wiki. It's not a very good test, but I suppose it's something.
http://www.intertwingly.net/wiki/pie/UpdatedConformanceTests Regards James
