Ah, the perils of email readers with quote folding and issue trackers without it. The important part of Brett's email is that PEP 420 has started splitting the meta path finder and path entry finder APIs, but importlib still uses a single ABC for both of them. That's probably a mistake, and something we want to address prior to the release of 3.3. I'll create a separate issue for that.

I just pushed a docs update to the PEP 420 repo that should address all of my comments. I went ahead with the "regular package" -> "initialized package" and "sys path finder" -> "path entry finder" name changes - they just make more sense given the way the components are used.

I wanted to avoid "regular package" as I expect namespace packages to eventually become the norm and initialized packages the more unusual case.

"sys path finder" was simply misleading, as those finders are used for *all* path entries, including those in package __path__ attributes.

I haven't reviewed Eric's comments in detail, so I don't know if I also picked up all of those.