\end{methoddesc}
\begin{methoddesc}{previous}{}
-Set the cursor to the first item in the DB file and return it. The order of
-keys in the file is unspecified.
+Set the cursor to the first item in the DB file and return it. The
+order of keys in the file is unspecified. This is not supported on
+hashtable databases (those opened with \function{hashopen()}).
\end{methoddesc}
\begin{methoddesc}{last}{}
-Set the cursor to the last item in the DB file and return it. The order of
-keys in the file is unspecified.
+Set the cursor to the last item in the DB file and return it. The
+order of keys in the file is unspecified. This is not supported on
+hashtable databases (those opened with \function{hashopen()}).
\end{methoddesc}
\begin{methoddesc}{sync}{}