Standard reminder: You can directly apply all the suggestions you want in one go by going to Files changed -> Clicking Add to batch on each suggestion -> When done, clicking Commit

Basic requirements (all PEP Types)

• Read and followed PEP 1 & PEP 12
• File created from the latest PEP template
• PEP has next available number, & set in filename (pep-NNNN.rst), PR title (PEP 123: <Title of PEP>) and PEP header
• Title clearly, accurately and concisely describes the content in 79 characters or less
• Core dev/PEP editor listed as Author or Sponsor, and formally confirmed their approval
• Author, Status (Draft), Type and Created headers filled out correctly
• PEP-Delegate, Topic, Requires and Replaces headers completed if appropriate
• Required sections included
  • Abstract (first section)
  • Copyright (last section; exact wording from template required)
• Code is well-formatted (PEP 7/PEP 8) and is in code blocks, with the right lexer names if non-Python
• PEP builds with no warnings, pre-commit checks pass and content displays as intended in the rendered HTML
• Authors/sponsor added to .github/CODEOWNERS for the PEP

Standards Track requirements

• PEP topic discussed in a suitable venue with general agreement that a PEP is appropriate
• Suggested sections included (unless not applicable)
  • Motivation
  • Rationale
  • Specification
  • Backwards Compatibility
  • Security Implications
  • How to Teach This
  • Reference Implementation
  • Rejected Ideas
  • Open Issues
• Right before or after initial merging, PEP discussion thread created and linked to in Discussions-To and Post-History

FWIW, this is pretty huge improvement over last time; thanks @fridex and everyone who contributed! Other than a grab-bag of requested fixes (nearly all one-click suggestions), I only have a handful of higher-level comments/missing pieces, most if not all of which should be fairly straightforward to add.

Higher-level comments for after suggestions are applied:

• I suggest include a brief Rationale section describing the reasoning behind the approach chosen in this PEP, and/or a brief history of the discussions that led to this PEP being proposed
• A security implication section should at least briefly mention the security benefits to this proposal, and any potential issues it may have
• A one-line "How to teach this" section could simply state that this metadata is intended for tools and is not directly visible to end users.
• A Reference Implementation section should highlight and link the PRs you've already prepared (sort of similar to what you previously put in the "References" section instead
• By standard convention, Backward Compatibility goes directly after the specification, not at the very end after Rejected Ideas and Open Issues

Great job adding a detailed and complete Rationale section; thanks! I have some textual copyedits, fixes and refinements on that, but otherwise this is looking pretty good to go on my end, pending final review and approval from @dstufft and any other subject-matter experts. Thanks!

Various suggestions on the added content (many related to removing an unnecessarily-complex layer of link indirection, as well as some grammar and other textual fixes), as well as a couple broader comments—most notably, I recommend moving the comprehensive tool survey to an appendix (as described in more detail in a comment below). Thanks!

Just a couple last small syntax fixes (as suggestions); otherwise LGTM from me! Thanks so much for your patience and hard work on this, @fridex !

Also, just BTW—after much testing, I was able to isolate an edge-case issue with our code where the References section in your PEP wasn't being properly hidden, due to containing reference names that duplicate/shadow implicit section title references (which isn't a problem, so long as you don't use them...one more reason not to). I've submitted PR #3083 to take care of that (which isn't a blocker to merging this one).

LGTM as a PEP editor; thanks again for all your hard work on this @fridex , and the many others who contributed so far! I'll leave it to @dstufft for his review as the sponsor and subject matter expert.

This looks great to me!