This page is named CacheControlPrivate.html, and was sent with the response header Cache-Control: private. This header is part of the HTTP/1.1 standard, but is not intended to influence whether a web browser caches a response to persistent storage or not. It is intended to apply to caching proxy servers that are shared by multiple users. With the exception of those browsers that do not cache HTTPS content at all, all browsers will write this page to the disk cache.