Written by: Dole-A-Holic 13/01/2007 16.44
I'm sure one of the other mods here would know that. Lita79 I'm looking in your direction.
As Dole said, it's a sort of a grahical representation of your post counter.
At 25 post you get your first white box, and you get one more (up to a total number of 7) every 25 posts.
At 200 posts (=25x8) you get a yellow box, same thing as before but every 200 posts.
At 1,600 posts (=200x8) you get a red box, same as before but every 1,600 posts.