sitemap.xml for auth sites

If you want the hidden content (behind a registration wall) be crawled by Google it's the only way. It needs to be public somehow.

403 are for then you are redirecting a user to a login page, in case they hit a registration wall. Those pages should have a 403. So that Google knows that you need to be logged in to view them. But if you want them to crawl the actual page, you need to automatically let them in and return 200.

The reason you can't find any information on the web on this, are that nobody does it... Either they are public or hidden.

OK, thank you very much. I've learned a lot.