It's a little suspicious. Why are they doing something that no other website in the world does? I was curious about zero-whatever but not enough to do whatever this is.

Plenty of sites do this, you just don't interact with them. Corp and govt intranets love this stuff.

Bruh it's one line in nginx config.

> that no other website in the world does

That you know of. Anywhere with stringent security it's everywhere.