Documentation

I think it must be, for the following reasons:

1. It is a stable API that exists since python3
2. It is implementing a builtin magic method__format__
3. It is quite useful for others
4. It is quite simple
5. There are no plans to remove / deprecate it
6. It is used in some parts of docs, example:https://github.com/python/cpython/blame/5ffdaf748d98da6065158534720f1996a45a0072/Doc/library/dis.rst#L1426

I will send a PR.

Linked PRs

• gh-102595: DocumentPyObject_Format c-api function #102596
• [3.10] gh-102595: DocumentPyObject_Format c-api function (GH-102596) #102878
• [3.11] gh-102595: DocumentPyObject_Format c-api function (GH-102596) #102879