I’ve now had some time to read the PEP, and I have a couple of high-level points I’d like to make.
First of all, the PEP is looking really good. A lot of work went into this, and it shows - thanks for sticking with it @brettcannon!
I don’t know if it’s just me, but I find it very hard to understand the structure of the lockfile from the field-by-field descriptions given. Would it be possible to add a “File Structure” section that have an overview of the structure of the file? Having a simple example of each of a file lock and a package lock lockfile (simplified to the point of only installing a single file/package, for brevity) actually in the PEP, rather than being linked, would also help.
Without an overview of the structure, I found it hard to follow the individual field descriptions, as I kept losing context.
In the “How to teach this” section, I think it would be worth including some comments on how to introduce users to the idea of having two types of locking - file locking and package locking. Tools will obviously have their own documentation, but if we introduce the concepts of file and package locking in the standards, tool documentation will need to change to be explicit about what they offer - and I think the PEP should make that clear.