Browser.cache.disk cache ssl
From MozillaZine Knowledge Base
Disk caching saves copies of the downloaded files on the hard drive so they doesn't need to be downloaded to be redisplayed. These pages can be viewed by anyone with permission to the cache folder. Pages transmitted with SSL encryption often contain sensitive information and caching of these pages to disk may present a privacy risk. This preference controls whether to cache to disk pages that were transmitted with SSL encryption.
Possible values and their effects
Cache to disk content retrieved by SSL. (Default)
Don't cache to disk content retrieved by SSL.
First checked in
Has an effect in