Jeff King [off-list ref] writes:
That being said, people other than Junio may apply your patch, so if you
are going to use such a marker, making it look scissor-like is probably
the best thing to do.
FWIW, I do run "am -sc3" from inside Emacs. It is a good idea to use what
is already accepted by the tool than coming up with a random convention of
your own anyway, so if somebody really wants to do "introductory comments
in discussion and then a patch", "-- >8 --" without quotes alone on a line
would be an appropriate thing to use.