Hacker News new | past | comments | ask | show | jobs | submit login

I've long been curious how exactly they determine the "registered domain", and your comment made me finally look for the answer. It looks like they use (and semi-manually maintain) a list of "effective TLDs": https://www.publicsuffix.org/

The maintenance process is described here: https://github.com/publicsuffix/list/wiki/Guidelines

Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact