Web Cache and cookies - need to understand a bit more!

Question

FROM THE ORACLES DOCS
If a document contains a cookie, then Oracle Web Cache evaluates the cookie value of the browser request and application Web server response. If the values match and there is a corresponding cacheability rule, then Oracle Web Cache caches the response. Because a session value change does not necessarily indicate a change of state on the application Web servers, session cookie values are not evaluated. For documents that use these cookies, the response is cached, regardless of whether or not the cookie values match.
OK so does this mean that if I have a site that has a single persistent cookie that say contains the username and the cookie is global over the site i.e. its set for the root "/" then inheritently WebCache cannot cache any page on this site even if the cacheability rule make no mention of cookies as the request and response cookie will be different ie user "bill" goes for first page and WC caches it then user "larry" asks for a page and becuase the request cookie is "larry" and the response is "bill" then it wont cache it even though this particular pages content may make no use of the cookie value.
Also does it mean that if I have a session cookie say for "authenticated" even if I have expressed that the cookie be used to cache different version of the page its no use WebCache will ignore it and simply cache one version for all even though this particular page maybe be different for authenticated and non authenticated users.
Sorry but its not clear just how WC works with cookies.
Thanks for any assistance
Rob

Answer 1

I asked one of the developers about this and here is the
response:
"I think he was not clear on 2 points:
1) we do not store any "Set-Cookie" header from the response.
all such headers are stripped when the document is inserted;
2) cookie comparison is only performed when we receive a response
from the os. On cache hits, no such comparison happens -- we
don't have anything to compare against as the cached documents
never contain any Set-Cookie headers
So in his example, after the response to Bill's request gets
cached (it's cached only when the non-session cookies in his
request and response match), Larry's request for the same URL
will get the cached document WITHOUT the "Set-Cookie" header. So
Larry gets a cache hit and his cookie will not get overwritten by
Bill's.
Now in 9.0 (the upcoming release), the cookie value comparison
only happens for multiversion cookies. So we are relaxing a bit
in that sense and will cache more documents than before.
As for his second part of the question (the authentication cookie
part), I'm not sure what exactly is the application behavior. Do
only authenticated users have the session cookie? If that's the
case, then, he can define a session caching rule to say "cache
with session, and cache without session, and the 2 versions are
different" (3 YES' on the 3 session definition questions). Then
we'll cache a version for the authenticated users (with session)
regardless of the session value, and another version for the
non-authenticated users(without session).
If, however, both authenticated and non-authenticated users have
the same session cookies with different values, and all
authenticated users map to one version of the doc and all
non-authenticated users map to another, then Web Cache can't
currently handle this. This is basically a multiversion cookie
rule, with some grouping of cookie values, which we don't support
yet."