[romanr]

I’ve read all the pages on that site and still don’t understand. And probably can be explained in one sentence by someone?

[seodisparate]

It looks like they want websites to do the following: whenever your website goes under a drastic change, serve the previous version of the website under a subdomain, and redirect all 404s on the newer version to the subdomain. More drastic changes in the future may potentially redirect 404s to previous subdomains/versions like a chain. At least that's my understanding of it.

[tarkin2]

It is poorly explained. I had to read the about page.

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?

[tartrate]

I didn't either, but now I do.

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.

[sokoloff]

I’d like to be able to show any eventual 404 from the current version of the site though, which means there may need to be a wrapper around the terminal site (or more reasonably, code that runs locally on the server to find the right page URL and 302 directly to that rather than a client round trip for every version searched).

[Signez]

You are not alone there. I tried multiple times to understand what the author tries to convey, without being really sure to grasp it.

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.

[sunaurus]

The idea is to keep all old versions of your website, and when somebody requests an URL, try to find that URL on all versions of your websites (starting with the newest), and only return 404 not found if the URL does not exist on any of the archived versions.

[phist_mcgee]

In a nutshell it is simply allowing you the ability to present fallback content with 302s but with a more gentle redirect than a 301, which tells you it is permanently gone.

[LudwigNagasena]

When you refactor your site, you put old content onto a subdomain and redirect there in case your new site doesn't have such page.

[Evansbee]

Don’t 404 links on your new site, 302 redirect to previous versions on different hosts until you run out, then 404.

[spydum]

think of it like having your 404 handler redirect to older versioned links maybe?