Forum Archive Enabled (yes/no)
The Search-Friendly Archive works only under the Apache web server with PHP compiled as a module.
It provides a basic structure that search engines can spider to grab all the content on your site.
Display Simple View of Threads (yes/no)
By default, threads in the Archive are displayed in a simple manner. Set this to no to have the real threads linked from the archive.
Forum Archive Threads Per Page (default: 250)
The number of threads to display per page in the threads listing.
This is done on a per-forum basis.
Forum Archive Posts Per Page (default: 250)
The number of posts to display per page in the thread listing.
Note:
On your own forum you can find the Archive here: http://www.yourforum.com/forumdir/archive/
(live example: http://www.vBulletin.com/forum/archive/)
(live example: http://www.vBulletin.com/forum/archive/)