Patch #1062033 / bug #1027771: clarify what happens when calling
insertBefore() with refChild=None.
diff --git a/Doc/lib/xmldom.tex b/Doc/lib/xmldom.tex
index e41d56c..317febb 100644
--- a/Doc/lib/xmldom.tex
+++ b/Doc/lib/xmldom.tex
@@ -340,7 +340,9 @@
\begin{methoddesc}[Node]{insertBefore}{newChild, refChild}
Insert a new child node before an existing child. It must be the case
that \var{refChild} is a child of this node; if not,
-\exception{ValueError} is raised. \var{newChild} is returned.
+\exception{ValueError} is raised. \var{newChild} is returned. If
+\var{refChild} is \code{None}, it inserts \var{newChild} at the end of
+the children's list.
\end{methoddesc}
\begin{methoddesc}[Node]{removeChild}{oldChild}