Strat-O-Matic Baseball 365

I'm fairly new to strat-o-matic online and I'm trying to understand the player sets better. I can find the ATG8 set, and a few variations of it, where can I find the player set for, for example, ATG8 r100390? What is the r100390 part of the set?

Thanks for your help.

When you start a new team look in the "Shuffle The Deck" box in the ATG8 area. There are a bunch of random and custom sets to choose from..

Thank you. I found those.