Add a note that the quoteattr() function is useful for HTML and SGML
attributes as well.
diff --git a/Doc/lib/xmlsaxutils.tex b/Doc/lib/xmlsaxutils.tex
index 0048485..6ab8d4a 100644
--- a/Doc/lib/xmlsaxutils.tex
+++ b/Doc/lib/xmlsaxutils.tex
@@ -38,6 +38,8 @@
 <element attr="ab ' cd &quot; ef">
 \end{verbatim}
 
+  This function is useful when generating attribute values for HTML or
+  any SGML using the reference concrete syntax.
   \versionadded{2.2}
 \end{funcdesc}