I’ve read all the pages on that site and still don’t understand. And probably can be explained in one sentence by someone?
Instead of 404s, you redirect to a previous version of your webserver (that is still running), which then instead of 404s redirects to a previous version of your site (that is still running), and eventually it tries the wayback machine.
So never pull down a previous version of your website, and issue 302s to that?
The site is suggesting a best practice to 302 FOUND-redirect you from:
<version x>.site.com
to: <version x-1>.site.com
Until it goes beyond the oldest version in which case you end up with a 404.At first I thought that it was simply some advocacy for taking the time to route legacy content using 302, but it also seems to be some sub-domain trick with years…?
It's really confusing to me.