diff --git a/README.org b/README.org
index fb27a9f..751fd56 100644
--- a/README.org
+++ b/README.org
@@ -622,7 +622,8 @@ should be used depending on the source block language by setting,
 
 When `org-fontify-quote-and-verse-blocks' is not nil, text inside
 verse and quote blocks are fontified using the `org-verse' and
-`org-quote' faces, which inherit from `org-block'.")
+`org-quote' faces, which inherit from `org-block'."
+    :group 'org-faces)
 
   (defface org-table
     ;; https://emacs.stackexchange.com/a/9604 answers:
@@ -635,7 +636,8 @@ verse and quote blocks are fontified using the `org-verse' and
        :inherit (fixed-pitch)
        ,@(and (>= emacs-major-version 27) '(:extend t))
        :background "#FFFFD0"))
-    "My face for tables."))
+    "My face for tables."
+    :group 'org-faces))
 #+end_src
 
 #+caption[Shadow Emacs font-lock faces to improve the readability]:
@@ -651,7 +653,8 @@ verse and quote blocks are fontified using the `org-verse' and
        (:foreground "magenta"))
       (t
        (:weight bold)))
-    "My face to show a here-document."))
+    "My face to show a here-document."
+    :group 'sh-indentation))
 
 (require 'org)
 #+end_src
@@ -3067,7 +3070,7 @@ the user-friendliness of this facility to a level acceptable for my workflow:
 (ensure-package-installation 'engrave-faces)
 
 (defun org-latex-engraved-source-block-filter (data _backend _info)
-  "Replace \"Code\" with \"Breakable\" in non-floating environments.
+  "Replace \"Code\" with \"Breakable\" in non-floating DATA environments.
 
 Set `org-latex-engraved-preamble' to define a Breakable (non-floating)
 environment and an unbreakable Code (floating) environment."
@@ -3382,7 +3385,7 @@ The following posts provide programming information:
 #+begin_src emacs-lisp -n :results silent
 ;; https://bitspook.in/blog/extending-org-mode-to-handle-youtube-paths/
 (defun org-yt-emms-open (path)
-  "Open an \"YouTube\" link with `emms' using \"mpv\"."
+  "Open an \"YouTube\" PATH link with `emms' using \"mpv\"."
   (let ((url (format "https://www.youtube.com/watch?v=%s" path)))
     (require 'emms nil 'noerror)
     (emms-add-url url)
@@ -3392,12 +3395,12 @@ The following posts provide programming information:
         (emms-playlist-mode-play-current-track)))))
 
 (defun org-yt-url-browse-open (path)
-  "Open an \"YouTube\" link with `url-browse'."
+  "Open an \"YouTube\" PATH link with `url-browse'."
   (let ((url (format "https://www.youtube.com/watch?v=%s" path)))
     (browse-url url)))
 
 (defun org-yt-export (path desc backend _)
-  "Export an \"YouTube\" link."
+  "Export an \"YouTube\" PATH link according to DESC and BACKEND."
   (pcase backend
       (`html
        (format "<iframe
@@ -3838,7 +3841,7 @@ converts to
 
   ;; Push the filter on the hook.
   (cl-pushnew #'org-latex-header-blocks-filter
-              org-export-before-parsing-hook))
+              org-export-before-parsing-functions))
 #+end_src
 
 This file uses the new most simple way, while keeping the deprecated ways for
@@ -5022,6 +5025,7 @@ post.
      . lisp-font-lock-syntactic-face-function)))
 
 (defun cl-init-lisp-font-lock ()
+  "Hook to initialize Common Lisp font locking."
   (setq font-lock-defaults cl-font-lock-defaults))
 
 (add-hook 'lisp-mode-hook 'cl-init-lisp-font-lock)
@@ -5654,7 +5658,8 @@ Available versions: 0.2.0, 0.1.1, 0.1.0
 (defvar pip-outdated-packages nil
   "Outdated Python packages.")
 
-(defun pip--list-outdated-sentinel (process event)
+(defun pip--list-outdated-sentinel (process _event)
+  "Sentinel function for when the `pip-list-outdated' PROCESS succeeds."
   (when (and (eq (process-status process) 'exit)
              (zerop (process-exit-status process))
              (buffer-live-p (process-buffer process)))
@@ -5672,7 +5677,7 @@ Available versions: 0.2.0, 0.1.1, 0.1.0
       (message "Calling `%S' succeeded" #'pip-list-outdated))))
 
 (defun pip-list-outdated ()
-  "Save the outdated Python packages in `pip-outdated-packages'
+  "Save the outdated Python packages in `pip-outdated-packages'.
 
 This invokes an asynchonous process and finishes with a message."
   (interactive)
@@ -5689,7 +5694,8 @@ This invokes an asynchonous process and finishes with a message."
 #+caption: Emacs interface to upgrade outdated unfrozen Python packages.
 #+name: lst:pip-upgrade-maybe
 #+begin_src emacs-lisp :results silent
-(defun pip--upgrade-maybe-sentinel (process event)
+(defun pip--upgrade-maybe-sentinel (process _event)
+  "Sentinel function for when the `pip-upgrade-maybe' PROCESS succeeds."
   (when (and (eq (process-status process) 'exit)
              (buffer-live-p (process-buffer process)))
     (display-buffer (process-buffer process))))