From ed943db794987cb6fc87b55d68d6164190ba9a24 Mon Sep 17 00:00:00 2001
From: Lars Ingebrigtsen <larsi@gnus.org>
Date: Sat, 8 Aug 2020 15:49:48 +0200
Subject: [PATCH] Document the OpenPGP header

* doc/misc/message.texi (Using the OpenPGP Header): Document the
OpenPGP header (bug#39964).
---
 doc/misc/message.texi | 23 +++++++++++++++++++++++
 etc/NEWS              |  1 +
 2 files changed, 24 insertions(+)

diff --git a/doc/misc/message.texi b/doc/misc/message.texi
index d8a889e29f3..d6df1a62cfd 100644
--- a/doc/misc/message.texi
+++ b/doc/misc/message.texi
@@ -1042,6 +1042,7 @@ and/or encrypted messages as explained in the following.
 * Signing and encryption::      Signing and encrypting commands.
 * Using S/MIME::                Using S/MIME
 * Using OpenPGP::               Using OpenPGP
+* OpenPGP Header::              Adding OpenPGP headers to messages.
 * Passphrase caching::          How to cache passphrases
 * PGP Compatibility::           Compatibility with older implementations
 * Encrypt-to-self::             Reading your own encrypted messages
@@ -1251,6 +1252,28 @@ according to two different standards, namely @acronym{PGP} or
 @code{mml-default-sign-method} determine which variant to prefer,
 @acronym{PGP/MIME} by default.
 
+@node OpenPGP Header
+@subsection OpenPGP Header
+
+The @samp{OpenPGP} header can be used to provide information about the
+sender's OpenPGP key.  This is a formalisation and modernisation of
+the non-standard @samp{X-PGP-Key} (etc.) headers that have been in use
+for a long time.  For more details, see
+@uref{https://tools.ietf.org/html/draft-josefsson-openpgp-mailnews-header}.
+
+@vindex message-openpgp-header
+To use this in Message, say:
+
+@lisp
+(add-hook 'message-send-hook 'messasge-add-openpgp-header)
+@end lisp
+
+Then customize the @code{message-openpgp-header} variable according to
+your PGP setup.  The variable is a list of the key ID, the key URL or
+ASCII armoured, and the protection preference, one of
+@samp{"unprotected"}, @samp{"sign"}, @samp{"encrypt"} or
+@samp{"signencrypt"}.
+
 @node Passphrase caching
 @subsection Passphrase caching
 
diff --git a/etc/NEWS b/etc/NEWS
index d2903449bed..269b07610a5 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -246,6 +246,7 @@ not.
 
 ** Message
 
++++
 *** Message now supports the OpenPGP header.
 To generate these headers, add the new function
 'messasge-add-openpgp-header' to 'message-send-hook'.  The header will
-- 
2.39.2