diff --git a/README.org b/README.org
index 4d181d6..052aa4f 100644
--- a/README.org
+++ b/README.org
@@ -918,6 +918,7 @@ The code in listing [[lst:customize-org-babel]], [[lst:customize-org]], and
                                   (python . t)
                                   (scheme . t)
                                   (shell . t)))
+     '(org-export-backends '(ascii beamer html icalendar latex odt texinfo))
      '(org-file-apps '((auto-mode . emacs)
                        (directory . emacs)
                        ("\\.mm\\'" . default)
@@ -1160,7 +1161,6 @@ this document to =html= and LaTeX correctly.
                  (org-element-parse-buffer 'greater-element nil) 'src-block
                (lambda (block)
                  (let ((name (org-element-property :name block)))
-                   (message "%s" name)
                    (when (and name (string-match-p infix name))
                      block))))))
         (dolist (block blocks)
@@ -1213,6 +1213,9 @@ new [[info:org#Editing Source Code][<LANGUAGE>-modes]]: =latex-header= and =late
       '((:exports . "results") (:results . "raw")))
 
     (defun org-babel-execute:latex-header (body _params)
+      "Execute a block of LaTeX preamble lines with org-babel.
+  This function is called by `org-babel-execute-src-block' and
+  prefixes all lines with \"#+latex_header: \"."
       (prefix-all-lines "#+latex_header: " body))
 
     (add-to-list 'org-src-lang-modes '("latex-extra-header" . latex))
@@ -1221,6 +1224,9 @@ new [[info:org#Editing Source Code][<LANGUAGE>-modes]]: =latex-header= and =late
       '((:exports . "results") (:results . "raw")))
 
     (defun org-babel-execute:latex-extra-header (body _params)
+      "Execute a block of LaTeX preamble lines with org-babel.
+  This function is called by `org-babel-execute-src-block' and
+  prefixes all lines with \"#+latex_extra_header: \"."
       (prefix-all-lines "#+latex_extra_header: " body)))
 #+end_src