I know what that is. If there's a black dot in the center of the envelope, it means that you've participated in that particular thread. It makes it easier to scan through the forums and find posts that you know you've made a post in.
A forum community dedicated to hunting and fishing enthusiasts in the Michigan area. Come join the discussion about safety, gear, tackle, tips, tricks, optics, hunting, gunsmithing, reviews, reports, accessories, classifieds, and more!