Variable: message-subject-re-regexp

message-subject-re-regexp is a customizable variable defined in message.el.gz.

Value

"\\`[   ]*\\(\\(RE\\|RÉ\\.?\\|FWD?\\|رد\\|回复\\|回覆\\|SV\\|Antw\\.?\\|VS\\|REF\\|AW\\|ΑΠ\\|ΣΧΕΤ\\|השב\\|Vá\\|R\\|RIF\\|BLS\\|RES\\|Odp\\|YNT\\|ATB\\)\\(([0-9]+)\\|\\[[0-9]+\\]\\|\\^[0-9]+\\)? ? *[:：﹕︓៖][        ]*\\)*[         ]*"

Documentation

Regexp matching "Re: " in the subject line.

Matching is done case-insensitively. Initialized from the value of mail-re-regexps, which is easier to customize.

This variable was added, or its default value changed, in Emacs 31.1.

Probably introduced at or before Emacs version 31.1.

Source Code

;; Defined in /usr/src/emacs/lisp/gnus/message.el.gz
(defcustom message-subject-re-regexp
  (mail--wrap-re-regexp
   (concat
    "\\("
    (string-join mail-re-regexps "\\|")
    "\\)"))
  "Regexp matching \"Re: \" in the subject line.
Matching is done case-insensitively.
Initialized from the value of `mail-re-regexps', which is easier to
customize."
  :group 'message-various
  :link '(custom-manual "(message)Message Headers")
  :type 'regexp
  :set-after '(mail-re-regexps)
  :version "31.1")