PlayStation Little Boxes?

When selecting a scenario, I noticed a tick beside the ones I have already played. But there are about 4 or 5 little boxes in each scenario window, anyone any idea what they are?

Thanks

 

Maybe level of difficulty, not entirely sure

 

Those denote level of difficulty

 

They denote the complexity of the scenario and go from 1 to 5, so a 1 or 2 will be standard, easy, few speed changes, nothing unusual happening, 3 or 4 usually involves a fair amount of speed changes, adverse signals or other requirements and 5 is difficult, usually involving loads of changes, adverse signals including stops, maybe a diversion or end reversal etc

 

Thanks