Drupal : Using HTTP Cache
By Mathieu CARBONNEAUX
the idea is to correctly position cache headers at the drupal level so that all intermediate caches such as outgoing proxies, browser caches or reverse proxies installed in front of the drupal website can cache efficiently…
I’ve written a doc on the subject… I think I’ll publish it on this site…
http://nadeausoftware.com/articles/2007/03/speed_drupal_web_site_enabling_page_caching#HowtoenableDrupalpagecaching