gnus-extra-headers

[Colin Baxter <m43cap@yandex.com>]

Hello,

If emacs (tested with 27.2 and 28.0.50) is launched with -Q (or
gnus-extra-headers has not been set explicitly by the user) then the
variable gnus-extra-headers has the value:

--8<---------------cut here---------------start------------->8---
gnus-extra-headers is a variable defined in ‘gnus-sum.el’.
Its value is
(X-Diary-Time-Zone X-Diary-Dow X-Diary-Year X-Diary-Month X-Diary-Dom X-Diary-Hour X-Diary-Minute To Cc Keywords Gcc Newsgroups X-GM-LABELS)
Original value was 
(To Cc Keywords Gcc Newsgroups X-GM-LABELS)

  You can customize this variable.


This variable was introduced, or its default value was changed, in
version 25.1 of Emacs.

Documentation:
Extra headers to parse.
--8<---------------cut here---------------end--------------->8---

The X-Diary settings seem to come from nndiary.el, but there is nothing
in the doc-string to indicate this.

Is this a bug? Is not the "Original value" of gnus-extra-headers incorrect?

Best wishes,

Colin Baxter.