On http://xenforo.com/community/, the info that shows as "pop up" when pointing the mouse on "sub-forums: 1" under Xenforo Bug Reports did not make it clear to me what the sub-forum was.
I went into the forum to see the subforum, after which I noticed the link below in the "pop up" was the subforum. I somehow did not look at it the first time.
It's actually quite obvioulsy there, maybe I had "link blindness" the first time I saw the "pop up" because the text "sub-forums" and the actual subforums links are seperated by white area and a line.
Making it more clear the text "sub-forums" is the header of the links below might improve usability.
This is obviously a very minor detail but wanted to report what I experienced exploring this great forum software.