Block comments from search engine indexing

I remember there used to be an option on WordPress to block comments from search engine indexing. I can’t find it anywhere, though.

Does anyone have suggestions or alternatives? Thanks.

To my knowledge, there is no easy way to achieve what you want. What I think you would need to do is two parts:

1. Detect page views by search engine spiders
2. In your page templates, only include include the comments when the viewer is not a search engine spider. Should be straightforward, but not trivial.

Good luck!