caching - 默认情况下缓存控制是公共(public)的还是私有(private)的？

Question

如果我不指定 public或 private Cache-Control 中的指令 header ，默认行为是什么？它是否可以被代理服务器缓存？

Answer 1

在 webmasters.stackexchange.com 上找到了答案.引用:

See http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9.3:

The max-age directive on a response implies that the response is
cacheable (i.e., "public") unless some other, more restrictive cache
directive is  also present. 

It's conceivable (likely?) that there are proxies in the wild which break this but since the only failure mode could be treating a public resource as private the consequences should be minimal beyond a modest performance hit. You'll have far more problems with proxies which do things like cache resources far beyond your specified max-age.