diff --git a/README.org b/README.org
index 0b1ab2a..07884fe 100644
--- a/README.org
+++ b/README.org
@@ -4721,8 +4721,10 @@ it for this buffer is by typing {{{kbd(C-c C-e t U)}}} to export the it to a
 :CUSTOM_ID: sec:which-function-mode
 :END:
 
-The code in listing [[lst:setup-which-function-mode]] has stolen ideas from the
-following links:
+The post [[https://codelearn.me/2024/02/02/emacs-which-function-mode.html][Emacs: which-function-mode]] claims that ~which-function-mode~ works in
+~org-mode~.  This is true in case all document headlines are simple, but is not
+true in case document headlines contain links.  The code in listing
+[[lst:setup-which-function-mode]] has stolen ideas from the following links:
 - [[https://list.orgmode.org/20240205.141235.268481480563517065.teika@gmx.com/][Show current org-mode headline in frame header]].
 - [[https://emacs.stackexchange.com/questions/30894/][Show current org-mode headline in modeline]].
 
@@ -4735,30 +4737,32 @@ following links:
 
 (defvar which-func-functions nil)
 
-(defun which--org-function ()
+(defun which-func-org-function ()
   "Return level and title of the current headline.
 Return the document title when point is above the first headline."
-  (interactive) ;; Keep this function interactive for debugging.
+  (interactive) ;; Keep this function interactive for fixing.
   (when (eq major-mode 'org-mode)
     (let (text)
+      ;; Handle point eventually above the first headline.
       (unless (org-at-heading-p)
         (save-excursion
           (org-previous-visible-heading 1)
           (let ((eap (org-element-at-point)))
             (when (org-element-type-p eap 'keyword)
               (setq text (format "0|%s" (org-element-property :value eap)))))))
+      ;; Handle point anywhere else.
       (unless text
         (let* ((chain (org-get-outline-path t))
                (count (length chain)))
           (setq text (format "%s|%s" count (nth (1- count) chain)))))
       text)))
 
-(add-to-list 'which-func-functions 'which--org-function)
+(add-to-list 'which-func-functions 'which-func-org-function)
 
-(defun which--pdf-function ()
+(defun which-func-pdf-view-function ()
   "Return the title of the current headline.
 Return \"Front Matter\" when point is above the first headline."
-  (interactive) ;; Keep this function interactive for debugging.
+  (interactive) ;; Keep this function interactive for fixing.
   (when (eq major-mode 'pdf-view-mode)
     (let* ((current-page (pdf-view-current-page))
            (outline (pdf-info-outline (current-buffer)))
@@ -4774,7 +4778,7 @@ Return \"Front Matter\" when point is above the first headline."
         (cl-incf hl-index))
       (if (< current-page hl-page) old-title new-title))))
 
-(add-to-list 'which-func-functions 'which--pdf-function)
+(add-to-list 'which-func-functions 'which-func-pdf-view-function)
 #+end_src
 
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