What are those little symbols mean next to some of the threads on here?

[Eric]

Just curious about those little symbols next to some threads that I see on this site. Like 'unhappy faces' and 'rainbows'. I see the rainbow symbol a lot around here....... Come to think of it, I also see the rainbow symbol all over the place in the gay section of West Hollywood whenever I visit my mom! Lol! And now I just noticed the icon selections you can choose from for a new post. Maybe it's just silly internet goofiness or something. Just curious.