diff --git a/README.org b/README.org
index d48e9bc..c9f65d6 100644
--- a/README.org
+++ b/README.org
@@ -1864,6 +1864,7 @@ file.
 #+name: lst:maybe-read-only-in-outline-mode
 #+begin_src emacs-lisp -n :results silent
 (defun maybe-read-only-in-outline-mode ()
+  "Check whether to open a file in `outline-mode' with `read-only-mode' enabled."
   ;; GAV: Should be a toplevel function to call `message' here.
   (let ((fnsd (buffer-file-name)))
     ;; GAV: `fnsd' is nil during Org export to LaTeX.