Technical note:    10020
  Created:           05/24/95 by Trip
  Last modified:     07/10/95 by Brian
  Product:           Netscape Navigator

Contrary to popular belief, pressing the Reload button does not force
the Netscape Navigator to reload the current page and all its graphics
from the server.

Instead, the Navigator carefully keeps track of the "last modified"
times of all of the web pages and graphics it has in its cache.  When
you press "Reload", the Navigator lets the server know that it needs
updated copies of the files for the current page IF THE COPIES ON THE
SERVER HAVE BEEN MODIFIED since the Navigator got the copies it
currently has stored in its cache.  If the "last modified" date on the
server is not later than the "last modified" date on the copy in the
Navigator´s cache, then the Navigator shows you the copy of the file
from its cache rather than bothering to pull a new copy of the file
down over the network.

Usually this works fine, and the behavior is slightly faster but
otherwise indistinguishable than if new copies of the files were
always grabbed from the server.  However, if the copy of the file on
the server has changed in some fashion that isn´t reflected in the
file's "last modified" timestamp (for example, maybe the file uses a
server-side include or maybe it has a custom trailer attached to it),
or if the server´s clock is wrong, then the Reload button might not
notice anything different on the server and it will keep showing you
the copy of the file from its local cache.

You can always work around this by going into the Netscape
preferences, clearing your cache (disk and/or memory, whichever is
available to you), then quitting out of Netscape, relaunching it, and
reloading the page you want to see.

Note that all of the above isn´t relevant for a given page if the
Navigator doesn´t have that page in its cache, in which case it will
always load the file directly from the web server.