diff --git a/site-lisp/ox-svg4css/ox-svg4css.el b/site-lisp/ox-svg4css/ox-svg4css.el
index dd7aa64..6654c38 100644
--- a/site-lisp/ox-svg4css/ox-svg4css.el
+++ b/site-lisp/ox-svg4css/ox-svg4css.el
@@ -7,7 +7,7 @@
 ;; Keywords: org, hypermedia
 
 ;; See the Emacs ox-html library for its authors, maintainer and FSF
-;; Copyright, since ox-svg4css contains a lot of code from the ox-html.
+;; Copyright, since ox-svg4css contains a lot of code from ox-html.
 
 ;; This file is NOT part of GNU Emacs.
 
@@ -33,15 +33,15 @@
 ;;    embed the SVG image in an <object> tag.
 ;; 2. If not, it checks `svg-inclusion' and "image in-lining"
 ;;    whether to copy the SVG contents to the HTML output.
-;; 3. If not, it falls back to checking "image in-lining" to treat the
-;;    SVG image as any other image and to embed it in an <img> tag.
-;; 4. It is possible to set `svg-as-object' and `svg-inclusion':
+;; 3. If not, it falls back to checking "image in-lining" whether to
+;;    embed the SVG image in an <img> tag (as any other image type).
+;; 4. It is possible to set `svg-as-object' and/or `svg-inclusion':
 ;;    - For each SVG link by means of "#+ATTR_HTML: :svg-as-object t"
-;;      and "#+ATTR_HTML: :svg-inclusion t".
-;;    - Within file scope by means of "#+OPTIONS: svg-as-object:t" and
+;;      or "#+ATTR_HTML: :svg-inclusion t".
+;;    - Within file scope by means of "#+OPTIONS: svg-as-object:t" or
 ;;      "#+OPTIONS: svg-inclusion:t".
 ;;    - Within toplevel scope by means of the options
-;;      `org-html-svg-as-object' and `org-html-svg-inclusion'.
+;;      `org-html-svg-as-object' or `org-html-svg-inclusion'.
 ;;
 ;; Caveats: the HTML output does not comply with W3C recommendations
 ;; after `svg-as-object' and/or `svg-inclusion' exports and it does not
@@ -54,6 +54,17 @@
 ;; "#+ATTR_HTML:" attributes to control the export options.
 ;;
 ;; I prefer enabling `:svg-as-object' over enabling `:svg-inclusion'.
+;;
+;; Relevant W3C documentation:
+;;
+;; Loading an SVG image by an HTML <embed>, <iframe> or <object> tag:
+;; https://stackoverflow.com/a/12604286
+;; https://svgwg.org/specs/integration/#referencing-modes
+;; https://svgwg.org/specs/integration/#embedded-document-mode
+;; https://svgwg.org/specs/integration/#dynamic-interactive-mode
+;;
+;; Four types of SVG document usage with their security implications:
+;; https://www.w3.org/wiki/SVG_Security
 
 ;;; Code: