[dsmithatx]

I believe it is actually the TOML format which was obviously inspired by .ini files.

TOML has a formal standard while ini files have no formal standard being the big difference.

[zaarn]

Git does not use TOML, even if it looks very similar. You can check the syntax in "man git-config", but is definitely has a few syntax differences to TOML (especially the "[section "subsection"]" part)

There is no formal git-config standard other than what's deployed in git.