--- loncom/html/adm/help/tex/Author_LON-CAPA_Introduction.tex	2017/01/19 21:12:45	1.13
+++ loncom/html/adm/help/tex/Author_LON-CAPA_Introduction.tex	2017/01/20 22:06:05	1.14
@@ -35,13 +35,25 @@ Once a resource has been published, the
 can be marked obsolete, and the version in your authoring space deleted,  but the published version(s) will remain in your folders in the locations in which
 they were originally published.
 
-\subsubsection*{The LON-CAPA markup language and the 5 editors}
+\subsubsection*{The LON-CAPA markup language}
 
 Content documents are created in the LON-CAPA markup language. Like HTML, which is the language used to create all content on the web, the LON-CAPA language is a \emph{markup language}. A markup language is simply structured with \emph{tags}: each structure in the document starts with a \emph{start tag} like \texttt{<problem>} and ends with an \emph{end tag} like \texttt{</problem>}.
 Additionally, each structure (called an \emph{element}) can have \emph{attributes}, each one composed of a name and a value. For instance, \texttt{<foil value="true">} starts a true foil.
 A markup language is defined essentially with a list of elements and attributes, and rules specifying which element is allowed inside which other element.
-The LON-CAPA language includes most HTML elements, and adds more elements which are described in this manual. The syntax is similar to HTML, but with an additional constraint: when an element is started with a start tag, it must always be closed with an end tag.
+
+The LON-CAPA language includes most HTML elements, and adds more elements which are described in this manual. The syntax is similar to HTML, but with an additional constraint: when an element is started with a start tag, it must always be closed with an end tag (unless the empty element syntax is used, as with \texttt{<hr/>}).
 This syntax is sometimes called ``XML'' in this manual. XML is a specific syntax for markup languages, but the LON-CAPA language is actually not using the XML syntax, which would require escaping special characters in scripts.
+
+HTML elements are not listed in this manual, but good resources are available on the web to learn HTML. For instance:
+\begin{itemize}
+\item Learn web development:\\
+\texttt{https://developer.mozilla.org/en-US/docs/Learn/HTML}
+\item HTML element reference:\\
+\texttt{https://developer.mozilla.org/en-US/docs/Web/HTML/Reference}
+\end{itemize}
+
+\subsubsection*{Five editors}
+
 \bigbreak
 The authoring environment currently includes 5 different editors:
 \begin{itemize}