What do the icons mean?!

What do the icons mean beside a topic?

well…
Sticky grenade means stick topic.
the ! means “READ THIS THREAD!”

Exclamation: Announcement. Always shows up at the top of all pages.
Plus: Recently-created thread.
Sticky: Pinned thread. Always shows up at the top of the first page.
Check: Thread with a poll attached.

Green tint: New replies have been made since you last visited the thread.

No New Posts
Pinned/Sticky Topic
New Post
Announcement(Pinned topic that gets priority over normal pinned topics.)

Poll
Unread posts on Poll topic
Unread posts on Announcement topic
Unread posts on Pinned topic