add a couple missing items
diff --git a/Doc/lib/libcsv.tex b/Doc/lib/libcsv.tex
index cac39bc..9f9449b 100644
--- a/Doc/lib/libcsv.tex
+++ b/Doc/lib/libcsv.tex
@@ -170,6 +170,16 @@
\class{reader} or \class{writer} instance.
\end{classdesc*}
+\begin{classdesc}{excel}{}
+The \class{excel} class defines the usual properties of an Excel-generated
+CSV file.
+\end{classdesc}
+
+\begin{classdesc}{excel_tab}{}
+The \class{excel_tab} class defines the usual properties of an
+Excel-generated TAB-delimited file.
+\end{classdesc}
+
\begin{classdesc}{Sniffer}{}
The \class{Sniffer} class is used to deduce the format of a CSV file.
\end{classdesc}