You just don't remember anything anymore. IIRC, it was implemented around 2001. It was little more than a curiosity though, you may have just bypassed the little colored "pills" on comments, but aside from being angry about having foes, or happy about getting a new friend, nothing was really done with the feature.

I think that friends' posts had an extra point of moderation calculated for your display, though that feature might not have been present in early incarnations.

The point of it was letting you give free pass from the moderation for some people's comments always appearing for you, or hiding other people.

It still exists if you have the original discussion system enabled. I never moved on to the javascript-based one.