Atom and prev links

We have a mature atom implementation for distribution of event streams
and as always the devil is in the details...

The issue revolves around prev links. At some point on an atom feed
you will hit the current item, prev will point to the next item that
does not yet exist. Most implementations I can find 404 this uri and
the client has the logic to keep polling the 404. This seems off to
me, I would expect this to be a 204. Then if I change my uri structure
it becomes a 404, otherwise it would seem that if I change my uri
structure all prev uris would need to redirect to the new ones (which
would be a rather large undertaking).

I couldn't find any details on this in relevant specs, has anyone seen this?

Cheers,

Greg

-- 
Le doute n'est pas une condition agréable, mais la certitude est absurde.