Felipe Contreras [off-list ref] writes:

quoted

What are the examples you have in mind, code that we want to forbid
standalone from using?

init_copy_notes_for_rewrite(). Nothing outside the 'git' binary would
need that. If you disagree, show me an example.

"Nothing would need that", if you are talking about the current
codebase, I would agree that nothing would link to it.

But that is not a good justification for closing door to others that
come later who may want to have a standalone that would want to use
it.  Think about rewriting filter-branch.sh in C but not as a
built-in, for example.