Ævar Arnfjörð Bjarmason [off-list ref] writes:
It adds the value of:
* If you're looking at e.g. git-subtree's manpage it doesn't have it,
so we're clearly marking things that are part of git itself, also if
you're doing e.g. "man git-annex" (or other non-git.git tool)
somewhere.
* Once you're at the bottom of a manpage in e.g. a web view it's a
handy link back to the start, see
e.g. https://git-scm.com/docs/git-add#_git
OK, that's fair enough.
Thanks for a clarification.