Caching Question re Paging

All,

A hopefully quick and already discussed question about paging and its
interaction with web caches.

The recommendation in 6.2.6 is to allow the server to either issue a 200
with the full representation as the body, OR when it receives a Prefer
header that requests paging, to instead return a 303 redirecting to the
first page.

This seems like it will make web caches constantly invalidate the responses
as paging and non-paging clients make requests, thereby reducing the
ability for the infrastructure to cope exactly where it's most needed --
the large 200 responses.  This could be signaled to the web caches by
including a Vary header with the value of Prefer, but I don't see that
anywhere in the document.

According to 2616, 303 isn't cacheable without explicit cache control
headers but 200 is.  So with the Vary header, the small 303s should pass
through without disturbing the cached 200. In theory. I think :)

Am I missing something obvious that makes all of this null and void and
it's already been discussed and discarded as unnecessary?

Thanks!

Rob

-- 
Rob Sanderson
Information Standards Advocate
Digital Library Systems and Services
Stanford, CA 94305