On the Thread Listing for each forum, there are two colums of icons on the left hand side - the first one is a series of envelopes, and those have a key at the bottom of the page (New Post, Hot Thread, etc).

The second column is a series of, for want of a better word, document icons. These are usually white, but occasionally replaced with something else (a yellow 'cool', a question mark, a series of horiz bars)

What the heck are those about -specifically, the question mark. I can't find a key anywhere.

Thanks!

-Lou