\begin{table}%t7
%\centering
\par
  \caption{Parameter keywords used for the {\tt -TAB} algorithm.}
  \label{ta:TABkeys}
  \begin{tabular}{llc}
     \hline\hline
     Keyword & Use & Default \\
     \hline
     \PS{i}{{\tt 0}\Ci} & table extension name ({\tt EXTNAME}) & --- \\
     \PV{i}{{\tt 1}\Ci} & table version number ({\tt EXTVER}) & 1 \\
     \PV{i}{{\tt 2}\Ci} & table level number ({\tt EXTLEVEL}) & 1 \\
     \PS{i}{{\tt 1}\Ci} & column name for the coordinate \\
                     & \hspace{1em} array ({\tt TTYPE$n_1$}) & --- \\
     \PS{i}{{\tt 2}\Ci} & column name for the indexing          & \\
                     & \hspace{1em} vector ({\tt TTYPE$n_2$}) &
                                                       no index \\
     \PV{i}{{\tt 3}\Ci} & axis number ($m$) in array \PS{i}{{\tt
                        1}\Ci}  & 1 \\ 
     \hline
   \end{tabular}
\end{table}