Variable: message-completion-alist

message-completion-alist is a customizable variable defined in message.el.gz.

Value

(("^\\(Newsgroups\\|Followup-To\\|Posted-To\\|Gcc\\):" . message-expand-group)
 ("^\\([^ :]*-\\)?\\(To\\|B?Cc\\|From\\|Reply-to\\|Mail-Followup-To\\|Mail-Copies-To\\):" . message-expand-name))

Documentation

Alist of (RE . FUN). Use FUN for completion on header lines matching RE.

FUN should be a function that obeys the same rules as those of completion-at-point-functions.

This variable was added, or its default value changed, in Emacs 27.1.

Source Code

;; Defined in /usr/src/emacs/lisp/gnus/message.el.gz
(defcustom message-completion-alist
  `((,message-newgroups-header-regexp . ,#'message-expand-group)
    (,message-email-recipient-header-regexp . ,#'message-expand-name))
  "Alist of (RE . FUN).  Use FUN for completion on header lines matching RE.
FUN should be a function that obeys the same rules as those
of `completion-at-point-functions'."
  :version "27.1"
  :group 'message
  :type '(alist :key-type regexp :value-type function))