Maxim Dounin Wrote:

> The "proxy_cache_valid" directives are used if there are no
> Cache-Control/Expires to allow caching (or they are ignored with
> proxy_ignore_headers). That is, with "proxy_cache_valid" you can
> cache something which isn't normally cached, but they don't
> prevent caching of other responses.

That was my missing piece. Thanks so much!! Now it makes sense!

-R