\begin{table}%t7
\caption{\label{obsclasstab}Observation class definitions. }
\small
%\centering
\par
 \begin{tabular}{ccll}
\hline \hline
Class & \%age of 2XMM obs & Definition & Comment \\
\hline
0 & 38\% & bad area = 0\%                & no region has been identified for flagging \\
1 & 12\% & 0\% $<$ bad area $<$ 0.1\% 	 &  $\la$$3$ single detections \\
2 & 10\% & 0.1\% $\le$ bad area $<$ 1\%  & circular region with  $40\arcsec \la r \la 60\arcsec$ \\
3 & 25\% & 1\% $\le$ bad area $<$ 10\% 	 & circular region with $60\arcsec \la r \la 200\arcsec$ \\
4 & 10\% & 10\% $\le$ bad area $<$ 100\% &  circular region with $r \ga 200\arcsec$ \\
5 & \phantom{0}5\% & bad area = 100\%    & the whole field is flagged as bad
\\
\hline
\end{tabular} 	
\end{table}