What does it mean?

I just realized that certain PCB players have either 2 yellow or 3 green under their “Dirt Miner” status. What does this mean?

It indicates a rank on the forums. For example mine are 5 red squares whilst admin are 6 red squares.

Wait so trusted is 2 yellow and Donator is 3 green

Yep, the full list is:

Member - 1 Yellow
Trusted - 2 Yellow
Donator - 3 Green
Mod - 3 Yellow
Op - 4 Yellow
SOP - 5 Red
Admin - 6 Red

And the “X Miner” corresponds to your post count. The better the block, the more posts.