Cache cleanup keeps Netscape Navigator files current.

Question: What’s a cache cleanup? What does it do? I’m wondering because I get them all the time. – H.L.

Answer: A disk cache, as you probably know, is an area on the hard drive used by a browser (in this case, Netscape Navigator) to store files that it has displayed. These files are typically images, but can be HTML documents or any other files the browser finds on a web page.

When you close Netscape 3.x or 4.x, the program checks to see whether the files have an LMD – a “last modification date” – and it discards the files that don’t have one.

An LMD is a piece of information provided to the browser by the Web server that lets the browser know how old the file is. The next time the browser goes to that site, it uses this date information to check to see if a newer version of the file exists. If the file is the same age as before, it uses the cache version, which loads faster. If the file on the site is newer than the version in your cache, your computer will display that newer version.

Netscape periodically deletes files that don’t have LMDs because, without one, a file’s age can’t be determined.

The reason some files don’t have LMD is because some web servers don’t provide them. Some web servers also only provide an LMD for certain types of files.

The other thing that can trigger a cache cleanup is if you have two versions of Netscape on one computer, and they’re using the same disk cache. Each version removes the cache entries of the other version.

If you want to know more about what’s in your Netscape Navigator cache, type about:cache in the Netscape field where you would normally type a web addresses.