Sam Ravnborg [off-list ref] writes:
I looked at the source and found the -k option, but adding [PATCH]
should not be default behaviour so this is not the correct solution.
The "correct" solution depends on where you come from. That
extra [PATCH] is a carryover from BK days, I was told by Linus,
to make e-mailed things stand out --- I've never used BK but I
am guessing that things were not as obvious as our commit
messages, perhaps? We have "Author/Committer" distinction so
the [PATCH] marker is redundant.
The rewrite, "git-am" does not bother with adding [PATCH], but
the original "git-applymbox", being everyday Linus' tool, was
left as it was, not to disrupt the workflow of Linus.