Variable: rmail-font-lock-keywords
rmail-font-lock-keywords is a variable defined in rmail.el.gz.
Value
(("^\\(From\\|Sender\\|Resent-From\\):" quote rmail-header-name)
("^\\(Mail-\\)?Reply-To:.*$" quote rmail-header-name)
("^Subject:" quote rmail-header-name)
("^X-Spam-Status:" quote rmail-header-name)
("^\\(To\\|Apparently-To\\|Cc\\|Newsgroups\\):" quote rmail-header-name)
("[>|}]"
("\\=[ ]*\\(\\(\\([[:alpha:]]+[[:alpha:]0-9_.@-`'\"]*\\)?\\([>|}][ ]*\\)\\)+\\)\\(.*\\)"
(beginning-of-line)
(end-of-line)
(1 font-lock-comment-delimiter-face nil t)
(5 font-lock-comment-face nil t)))
("^\\(X-[a-z0-9-]+\\|In-Reply-To\\|Date\\):.*\\(\n[ ]+.*\\)*$" quote rmail-header-name))
Documentation
Additional expressions to highlight in Rmail mode.
Source Code
;; Defined in /usr/src/emacs/lisp/mail/rmail.el.gz
;; FIXME the rmail-header-name headers ought to be customizable.
;; It seems a bit arbitrary, for example, that all of the Date: line
;; gets highlighted.
(defvar rmail-font-lock-keywords
;; These are all matched case-insensitively.
(eval-when-compile
(let* ((cite-chars "[>|}]")
(cite-prefix "[:alpha:]")
(cite-suffix (concat cite-prefix "0-9_.@-`'\"")))
(list '("^\\(From\\|Sender\\|Resent-From\\):"
. 'rmail-header-name)
'("^\\(Mail-\\)?Reply-To:.*$" . 'rmail-header-name)
;; FIXME Mail-Followup-To should probably be here too.
'("^Subject:" . 'rmail-header-name)
'("^X-Spam-Status:" . 'rmail-header-name)
'("^\\(To\\|Apparently-To\\|Cc\\|Newsgroups\\):"
. 'rmail-header-name)
;; Use MATCH-ANCHORED to effectively anchor the regexp left side.
`(,cite-chars
(,(concat "\\=[ \t]*"
"\\(\\(\\([" cite-prefix "]+[" cite-suffix "]*\\)?"
"\\(" cite-chars "[ \t]*\\)\\)+\\)"
"\\(.*\\)")
(beginning-of-line) (end-of-line)
(1 font-lock-comment-delimiter-face nil t)
(5 font-lock-comment-face nil t)))
'("^\\(X-[a-z0-9-]+\\|In-Reply-To\\|Date\\):.*\\(\n[ \t]+.*\\)*$"
. 'rmail-header-name))))
"Additional expressions to highlight in Rmail mode.")