oh..well, I haven't made it that far yet, and please, anyone correct me, but..
I think there's a 256-folder limit in each of the categories..after that, it starts truncating (cutting off) parts of the name. Eventually, they get unreadable (at least by you..;) I've been told that you can stuff some things in the camera folder. Also, it will 'sort of' alphebetize items, with the ! character being on top (ever wonder why so many of your folders start with ! ? or !! ?..;)
We used to have occasional braggin' contests for the largest runtime (mine is a shamefully-small 1 gig, but then I'm running Poser 4 off of freebies..;) Stay tuned for more coherent and useful answers..;)

I wish I'd said that.. The Staircase Wit

anahl nathrak uth vas betude doth yel dyenvey..;)