diff --git a/content/posts/how-i-convert-pdfs-to-epub.adoc b/content/posts/how-i-convert-pdfs-to-epub.adoc
index 4f6f0e2..20cb48c 100644
--- a/content/posts/how-i-convert-pdfs-to-epub.adoc
+++ b/content/posts/how-i-convert-pdfs-to-epub.adoc
@@ -17,6 +17,7 @@ tags:
 :url-calibre: https://calibre-ebook.com/
 :url-calibre-convert: https://manual.calibre-ebook.com/conversion.html#pdfconversion
 :url-emacs: https://www.gnu.org/software/emacs/
+:url-emacs-key-notation: https://www.emacswiki.org/emacs/EmacsKeyNotation
 :wp-pdf: https://en.wikipedia.org/wiki/PDF
 :wp-epub: https://en.wikipedia.org/wiki/EPUB
 :wp-xhtml: https://en.wikipedia.org/wiki/XHTML
@@ -38,6 +39,10 @@ keyboard macros and some knowledge of link:{wp-xhtml}[XHTML] and
 link:{wp-css}[CSS] to follow this guide. It will take long and is boring, but
 the result is a clean and enjoyable book.
 
+[NOTE]
+I will use the link:{url-emacs-key-notation}[Emacs key notation] throughout this
+guide.
+
 == Create a new book in Calibre
 
 Click on menu:Add books[Add empty book]. Then fill in the metadata and select