from date id references chars lines xref extra.
In the case of a string value, if the @code{match} is a regular
-expression, a @samp{gnus-match-substitute-replacement} is proceed on
-the value to replace the positional parameters @samp{\@var{n}} by the
-corresponding parenthetical matches (see @xref{Replacing Match,,
-Replacing the Text that Matched, elisp, The Emacs Lisp Reference Manual}.)
+expression, or if it takes the form @code{(header @var{match}
+@var{regexp})}, a @samp{gnus-match-substitute-replacement} is proceed
+on the value to replace the positional parameters @samp{\@var{n}} by
+the corresponding parenthetical matches (see @xref{Replacing Match,,
+Replacing the Text that Matched, elisp, The Emacs Lisp Reference
+Manual}.)
@vindex message-reply-headers
;; @r{If I'm replying to Larsi, set the Organization header.}
((header "from" "larsi.*org")
(Organization "Somewhere, Inc."))
+ ;; @r{Reply to a message from the same subaddress the message}
+ ;; @r{was sent to.}
+ ((header "x-original-to" "me\\(\\+.+\\)@@example.org")
+ (address "me\\1@@example.org"))
((posting-from-work-p) ;; @r{A user defined function}
(signature-file "~/.work-signature")
(address "user@@bar.foo")