Variable: message-forward-included-headers
message-forward-included-headers is a customizable variable defined in
message.el.gz.
Value
("^From:" "^Subject:" "^Date:" "^To:" "^Cc:")
Documentation
If non-nil, delete non-matching headers when forwarding a message.
Only headers that match this regexp will be included. This variable should be a regexp or a list of regexps.
Also see message-forward-ignored-headers -- both variables are applied.
In addition, see message-forward-included-mime-headers.
When forwarding messages as MIME, but when
message-forward-show-mml results in MML not being used,
message-forward-included-mime-headers take precedence.
This variable was added, or its default value changed, in Emacs 27.1.
Probably introduced at or before Emacs version 27.1.
Source Code
;; Defined in /usr/src/emacs/lisp/gnus/message.el.gz
(defcustom message-forward-included-headers
'("^From:" "^Subject:" "^Date:" "^To:" "^Cc:")
"If non-nil, delete non-matching headers when forwarding a message.
Only headers that match this regexp will be included. This
variable should be a regexp or a list of regexps.
Also see `message-forward-ignored-headers' -- both variables are applied.
In addition, see `message-forward-included-mime-headers'.
When forwarding messages as MIME, but when
`message-forward-show-mml' results in MML not being used,
`message-forward-included-mime-headers' take precedence."
:version "27.1"
:group 'message-forwarding
:type '(repeat :value-to-internal (lambda (widget value)
(custom-split-regexp-maybe value))
:match (lambda (widget value)
(or (stringp value)
(widget-editable-list-match widget value)))
regexp))