git-commit: document log message formatting convention

diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt
index 305bd79154fabea871419ab56b4a6f01f58b6a57..67425dc0359ee9774200e1a2e12913d570117e7c 100644 (file)
--- a/Documentation/git-format-patch.txt
+++ b/Documentation/git-format-patch.txt
@@ -11,6 +11,7 @@ SYNOPSIS
 [verse]
 'git-format-patch' [-n | -k] [-o <dir> | --stdout] [--attach] [--thread]
                   [-s | --signoff] [--diff-options] [--start-number <n>]
+                  [--in-reply-to=Message-Id]
                   <since>[..<until>]
 
 DESCRIPTION
@@ -72,6 +73,11 @@ OPTIONS
        subsequent mails appear as replies to the first.  Also generates
        the Message-Id header to reference.
 
+--in-reply-to=Message-Id::
+       Make the first mail (or all the mails with --no-thread) appear as a
+       reply to the given Message-Id, which avoids breaking threads to
+       provide a new patch series.
+
 CONFIGURATION
 -------------
 You can specify extra mail header lines to be added to each