This page is named CacheControlPublic.html, and was sent with the response header Cache-Control: public. This header is part of the HTTP/1.1 standard, and indicates that the response "MAY be cached by any cache, even if it would normally be non-cacheable or cacheable only within a non-shared cache." Firefox 2.x and 3.x used an opt-in HTTPS caching policy. HTTPS responses would not be cached unless the server explicitly sent the Cache-Control: public header. With the exception of those browsers that do not cache HTTPS content at all, all browsers, including Firefox 2.x and 3.x, will write this page to the disk cache.