I know this is going to annoy a whole heap of people! And I thought I understood about blasted levels, but am now bloody confused!
The main stumbling block is, for example where does a full number - say a 2 sit, compared to the ones with the letter appended?
in my logical head I am assuming same as a 2b? got confused as was expecting report to be all whole numbers, or with the abc, not a combination of both 
First time we've seen kevels, and yes I know it doesn't matter in the grand scheme, but I just like to understand things!