docs: stable-kernel-rules: explain use of [email protected] (w/o @Vger.)

Document when to use of [email protected] instead of
[email protected], as the two are easily mixed up and their
difference not explained anywhere[1].

Link: https://lore.kernel.org/all/[email protected]/ [1]
Signed-off-by: Thorsten Leemhuis <[email protected]>
Reviewed-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Jonathan Corbet <[email protected]>
Link: https://lore.kernel.org/r/6783b71da48aac5290756343f58591dc42da87bc.1714367921.git.linux@leemhuis.info

Author: knurd

Documentation/process/stable-kernel-rules.rst

@@ -72,6 +72,10 @@ for stable trees, add this tag in the sign-off area::
 
   Cc: [email protected]
 
+Use ``Cc: [email protected]`` instead when fixing unpublished vulnerabilities:
+it reduces the chance of accidentally exposing the fix to the public by way of
+'git send-email', as mails sent to that address are not delivered anywhere.
+
 Once the patch is mainlined it will be applied to the stable tree without
 anything else needing to be done by the author or subsystem maintainer.