SubmittingPatches: document Based-on-patch-by trailer

This trailer comes up often enough and the use case is not fully covered
by the other trailers here. For example, it is sometimes better to use
this trailer instead of `Co-authored-by:`.

Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/SubmittingPatches b/Documentation/SubmittingPatches
index 8d946e9acb3143a4c7524c733c17928d80d966b6..5b4ab93543c86dbfafed708f6bb88d26305f3a97 100644 (file)
--- a/Documentation/SubmittingPatches
+++ b/Documentation/SubmittingPatches
@@ -465,6 +465,10 @@ These are the common trailers in use:
   and found it to have the desired effect.
 . `Co-authored-by:` is used to indicate that people exchanged drafts
    of a patch before submitting it.
+. `Based-on-patch-by:` is used when someone else authored parts of the
+  patch that you are submitting. This might be relevant if someone sent
+  a patch to the mailing list with their sign-off. (Be mindful and ask
+  them to sign off on it if they did not.)
 . `Helped-by:` is used to credit someone who suggested ideas for
   changes without providing the precise changes in patch form.
 . `Mentored-by:` is used to credit someone with helping develop a