It's part of the URL path. schema: http, domain: hintjens.com, url path: /blog:99 It looks a bit like a port number, but it's in the wrong place. For that you

It's part of the URL path. schema: http, domain: hintjens.com, url path: /blog:99 It looks a bit like a port number, but it's in the wrong place. For that you'd want http://hintjens.com:99/blog http://hintjens.com:99/blog