I have been wondering about the color coding of the icons on forum posts - sometimes gray, blue and red. Just as I was about to post asking the difference, I noticed the icon legend at the bottom! So now it makes sense.
Except... what makes a thread a "hot thread?" It doesn't seem to have anything to do with the amount of recent thread activity. Is it tagged somehow by the author? Or by site administrators?
After being a member for 2 years, it is time I learned something about how this works!