configure your firewall to accept anything from that one site
If we're still talking about HTTP_REFERER, that's information that your browser sends to the server.
It's only sent when you click on a link on a web page. For example, if you click a link on site A that goes to site B, then site B would (potentially) know that you came from site A.
It's not sent when you use a bookmark, a windows shortcut, or type a URL into the browser's address bar. If you use a bookmark to access site B, then site B does not know which page you last viewed.
So if you're concerned about a site running UBB.threads knowing "where you've been", you can simply use a bookmark to access the site.
