What does this mean?

[Alexandra Puppyblew]

There is a little icon of a thought balloon next to each topic. I've noticed most of them are orange, but I've seen some that are different. There's one that's grey with a little X in the middle. I think that one means it's locked. There are some that are orange but look faded, and I think I've seen red ones? Is there a key or something where it says what all these mean?

[Ruto]

There's s little legend at the bottom of a forum that will tell you what each bubble represents.

[Alexandra Puppyblew]

Oh, duh! :* Thanks. I looked everywhere, but apparently I never scrolled all the way down to the bottom.