The numbered and bulletted lists are indented from the body text, which looks good in the .rst, but causes the lists themselves to be blockquotes.  This leads to confusing formatting on python.org: https://www.python.org/dev/peps/pep-0420/

BTW: this formatting error is rampant among the PEPs... :(

OK, "rampant" was overly dramatic... :)

These PEPs seem to have the same issue:

pep-0302.html
pep-0327.html
pep-0339.html
pep-0362.html
pep-0364.html
pep-0372.html
pep-0380.html
pep-0382.html
pep-0393.html
pep-0400.html
pep-0403.html
pep-0404.html
pep-0410.html
pep-0416.html
pep-0418.html
pep-0426.html
pep-0432.html
pep-0433.html
pep-0437.html
pep-0446.html
pep-0457.html
pep-0461.html
pep-0472.html
pep-0488.html
pep-0498.html
pep-0628.html
pep-3103.html
pep-3104.html
pep-3108.html
pep-3121.html
pep-3127.html
pep-3131.html
pep-3137.html
pep-3141.html
pep-3147.html
pep-3149.html
pep-3150.html
pep-3156.html

For references:

PEP 0302: New Import Hooks
PEP 0327: Decimal Data Type
PEP 0339: Design of the CPython Compiler
PEP 0362: Function Signature Object
PEP 0364: Transitioning to the Py3K Standard Library
PEP 0372: Adding an ordered dictionary to collections
PEP 0380: Syntax for Delegating to a Subgenerator
PEP 0382: Namespace Packages
PEP 0393: Flexible String Representation
PEP 0400: Deprecate codecs.StreamReader and codecs.StreamWriter
PEP 0403: General purpose decorator clause (aka "@in" clause)
PEP 0404: Python 2.8 Un-release Schedule
PEP 0410: Use decimal.Decimal type for timestamps
PEP 0416: Add a frozendict builtin type
PEP 0418: Add monotonic time, performance counter, and process time functions
PEP 0420: Implicit Namespace Packages
PEP 0426: Metadata for Python Software Packages 2.0
PEP 0432: Simplifying the CPython startup sequence
PEP 0433: Easier suppression of file descriptor inheritance
PEP 0437: A DSL for specifying signatures, annotations and argument converters
PEP 0446: Make newly created file descriptors non-inheritable
PEP 0457: Syntax For Positional-Only Parameters
PEP 0461: Adding % formatting to bytes and bytearray
PEP 0472: Support for indexing with keyword arguments
PEP 0488: Elimination of PYO files
PEP 0498: Literal String Interpolation
PEP 0628: Add ``math.tau``
PEP 3103: A Switch/Case Statement
PEP 3104: Access to Names in Outer Scopes
PEP 3108: Standard Library Reorganization
PEP 3121: Extension Module Initialization and Finalization
PEP 3127: Integer Literal Support and Syntax
PEP 3131: Supporting Non-ASCII Identifiers
PEP 3137: Immutable Bytes and Mutable Buffer
PEP 3141: A Type Hierarchy for Numbers
PEP 3147: PYC Repository Directories
PEP 3149: ABI version tagged .so files
PEP 3150: Statement local namespaces (aka "given" clause)
PEP 3156: Asynchronous IO Support Rebooted: the "asyncio" Module

Looks pretty rampant to me :)

Anyway, +1 for fixing, you can just do it without review if you have the time.

New changeset 03a4c21ca991 by Berker Peksag in branch 'default':
Issue #26914: Fix formatting of lists in PEP 420
https://hg.python.org/peps/rev/03a4c21ca991

Thanks, I pushed pep-0420.patch.

New changeset d420d6fe349f by Georg Brandl in branch 'default':
Fix lists-in-blockquotes in 3xxx PEPs. Ref: #26914
https://hg.python.org/peps/rev/d420d6fe349f

New changeset d34c698f63a3 by Georg Brandl in branch 'default':
Fix lists-in-blockquotes in 0xxx PEPs. Ref: #26914
https://hg.python.org/peps/rev/d34c698f63a3

New changeset e7200e32b220 by Georg Brandl in branch 'default':
Fixup some more lists-in-blockquotes. Fixes #26914.
https://hg.python.org/peps/rev/e7200e32b220

Unless I have permissions I've never used, I don't think I can just push fixes to the peps repo. Also, it looks like Georg is working away at it!

Yep, they should all be gone. I tried to make sure by running the sources through docutils and finding nested <blockquote><foo_list> nodes.