Discuss Vary header

[binki]

I’m quite certain that the Vary header is meaningless in appcache. E.g., if you wanted to serve a different page based on language, you would have to make your site’s URIs vary by language too by using domains or lang=x query strings. If you try to use the Vary header and your application stores server-generated pages where the server outputs different results based on Vary, the user will only see the content as the browser accessed the website the first time.

This is my understanding/assumption, I have not actually tested for real.