Forum Icons

What do the icons in the leftmost column of the forum pages represent. I figured out a couple of them, like the paper-clip, but are they explained anywhere?

If you participated in the discussion, you'll see this:

The other ones can be picked by the user posting the message from the "Message icon:" drop down list in the editor.
It's an unimportant way to personalise the thread or to try to get someone's attention to your thread.
You found the paperclip yourself, which appears in case at least one post in the thread has an attachment.

Thanks. I never used the Message Icons because I dislike emoticons. But I can see the value in this case.