can someone explain the buses?

[kate_]

i'm talking about the little ones just below your name on the left when you make a post...it seems like the larger someone's post count is, the more buses they have...but that's not always the case, i've seen people with more posts and fewer buses..and why and when do they change colours? i recently had five buses i think, but now there's four and they're green...hmmm. i'm just wondering...something that i've been curious about for awhile

[Forget Me]

hey
an explanation of the buses can be found here
hope that helps