Criteria for replying to trade posts?

I noticed today that it now says I have "insufficient priveleges" to post responses to trade posts.

I hunted around for an explanation, and only found this:

"Replying is now a privilege that's limited to users who meet a specific combination of criteria. The goal is cultivate a group of trading mentors who can respond to threads/offers with helpful replies."

Are these criteria that allow one to respond explained somewhere? I couldnt find them, and was wondering what exactly they are.

Thanks!