what are the little

[Nord]

green things and yield signs under everyone's avitars???
How come I don't have a yield thingy like everyone else???

[HM]

Green means you are logged on. The yield thing is for crying to mommy about a bad post. You don't have one under your own as you are not gonna report on yourself.
If the light is grey, it means they are not online or are "hidden" so we can be sneaky.