I find the W3C's official Offline Web Applications specification to be rather vague about how the cache manifest interacts with headers such as ETag, Expires, or Pragma on cached assets. I know that the manifest should be checked with each request so that the browser knows when to check the other assets for updates.

If there are assets with an expiration date that is still in the future, will they be refreshed if the cache manifest is updated? Which caching mechanism takes precedence, and when?

I find the W3C's official Offline Web Applications specification to be rather vague about how the cache manifest interacts with headers such as ETag, Expires, or Pragma on cached assets. I know that the manifest should be checked with each request so that the browser knows when to check the other assets for updates. But because the specification doesn't define how the cache manifest interacts with normal cache instructions, I can't predict precisely how the browser will react.

Will assets with a future expiration date be refreshed (no matter the cache headers) when the cache manifest is updated? Or, will those assets obey the normal caching rules? 

Which caching mechanism, HTTP cache versus cache manifest, will take precedence, and when?