help-what-about.el

(defun help-what-about ()
  "Returns nil if called in non help-mode derived buffer.
Otherwise guesses what the help buffer is about.
If it succeeds the guess is returned as a string. Otherwise returns nil.

Heuristics:
If the buffer starts with a known symbol (i.e. in `obarray') that's our result.
This may return the wrong thing: imagine a mode where `t t' runs `foo', we will
think `describe-key' is talking about `t' alone.
If someone defines `Enabled' we will be similarly confused after `describe-mode', etc."
  (if (derived-mode-p 'help-mode)
      (let ((described-thing
             ;; (current-word t ...) protects us against things
             ;; like describe-char which start with spaces
             (save-excursion (progn (goto-char (point-min)) (current-word t nil)))))
        (if (or
             (intern-soft described-thing)
             ;; Special case since  (intern-soft "nil") ==> nil
             (string-equal described-thing "nil"))
            described-thing
          nil))))