Does Nginx's proxy cache support any kind of cache validation?

Hey guys,

I have been playing with proxy cache, works well enough except for one
issue.

My pages are localized (but use the same standard URL) and with other
systems I can use either the vary or etag header to notify the cache of
either updated content or simply a different version to serve. Nginx
doesn’t seem to be paying any attention to the etag so is this possible
to with Nginx right now in any capacity?

Posted at Nginx Forum:
http://forum.nginx.org/read.php?2,57772,57772#msg-57772