Cache-Control: private indicates that the resource is
cacheable but potentially different for every recipient, so shared
caches (squid, MS Proxy, etc) should not cache it while
private caches (your personal browser cache) can consider it
fully cacheable. While this is how we want ACS pages to be
treated it's probably not what you want for static HTML. No biggie,
really, but it means some content you're serving isn't being
treated as cacheable when it potentially should be.
