Variable: mail-citation-header
mail-citation-header is a variable defined in sendmail.el.gz.
Value
nil
Documentation
While running mail-citation-hook, this variable holds the message header.
This enables the hook functions to see the whole message header regardless of what part of it (if any) is included in the cited text.
Source Code
;; Defined in /usr/src/emacs/lisp/mail/sendmail.el.gz
(defvar mail-citation-header nil
"While running `mail-citation-hook', this variable holds the message header.
This enables the hook functions to see the whole message header
regardless of what part of it (if any) is included in the cited text.")