Re: info-lookup-alist mangled, breaks C-h S

[Eli Zaretskii]

Lars, your commit f839c7f, viz.:

  Author:     Lars Ingebrigtsen <larsi@gnus.org>
  AuthorDate: Sat Oct 9 14:44:21 2021 +0200
  Commit:     Lars Ingebrigtsen <larsi@gnus.org>
  CommitDate: Sat Oct 9 14:44:21 2021 +0200

      Make `C-h S' work on symbols from most of the manuals in Emacs

      * lisp/info-look.el (lambda): Add `C-h S' lookup for all the
      "misc" manuals in Emacs (bug#42753).

introduced a new form for HELP-MODE in info-look up-alist:

+(mapc
+ (lambda (elem)
+   (let* ((prefix (car elem)))
+     (info-lookup-add-help
+      :mode (cons 'emacs-lisp-mode prefix)  <<<<<<<<<<<<<<<<<

Now HELP-MODE could be a cons cell, not just a symbol.  But the doc
string of info-lookup-alist was not updated, and therefore the
semantics of this form is not documented.  What does that cons cell
value mean?