A short comment on table names.

doc/manual.tex

@@ -112,7 +112,9 @@ Each log will look something like this:
 \end{center}
 
 \section{New log}
-To create a new log, click \texttt{New Log} in the \texttt{Logbook} menu and enter the desired name of the log (e.g. repeater\_contacts, dx, mobile\_log). This name must be unique. Alternatively, use the shortcut key combination \texttt{Ctrl + N}.
+To create a new log, click \texttt{New Log} in the \texttt{Logbook} menu and enter the desired name of the log (e.g. repeater\_contacts, dx, mobile\_log). Alternatively, use the shortcut key combination \texttt{Ctrl + N}. 
+
+Note that the log name must be unique (i.e. it cannot already exist in the logbook). Furthermore, it can only be composed of alphanumeric characters and the underscore character, and the first character in the name must not be a number. 
 
 \section{Renaming a log}
 To rename the currently selected log, click \texttt{Rename Selected Log} in the \texttt{Logbook} menu. Remember that the log's new name cannot be the same as another log in the logbook.