[mooism2]

Afaik, HN uses rel=nofollow on all links below a certain score.

[gus_massa]

I looked in https://news.ycombinator.com/newest and apparently the nofollow disappears when the story gets 6 point. The number may change without prior notice. Perhaps they are using a more complicated secret criterion.

[timrivera]

Thanks for the heads up, I didn't know that.