Viewing available part count

[Orion Pobursky]

Okay thanks. I've also read the documentation is outdated, so I figured it was worth asking.

Another question I have: is it possible to filter the parts to a single set or list of sets? 

I figured out how to add a part list by dropping the file in the dir structure, but it would be more helpful if I could still use the existing part bin structure and limit the results to a narrow part list. 

Say I want to find all the bricks in my custom part list, etc.

I'm confused on what you're looking for. Do you want:
1) Only the parts in a MOC/custom model?
2) Only the parts in an official set
3) Only the parts in a custom part list (which is really just #1 restated)

All of these things are possible in one way or another.