From @ncoghlan in python/peps#3817 (comment):

I'm wondering if it might be worth adding more detail on immortal objects to a new subheading in https://docs.python.org/3/c-api/refcounting.html though, as the best canonical doc reference I could find in the reference docs is to the term reference count which really just mentions immortal objects rather than explaining them. A glossary entry referencing that new subsection would also be helpful.

The two explanatory links in the C API docs go to the PEP, which is about to be marked as no longer to be trusted as living documentation.

Linked PRs

• gh-120426: Reword the glossary term "immortal" #123191
• [3.13] gh-120426: Reword the glossary term "immortal" (GH-123191) #123491
• [3.12] gh-120426: Add the glossary term "immortal" (GH-123191) (GH-123491) #123636