\begin{table}%t1
\caption{Number of quasars cross-identified between the recent catalog 
of V\'{e}ron Cetty \& V\'{e}ron (\cite{Vero03}) and the three categories of catalogs 
used in the construction of the ICRF: 212~defining sources, 294~candidate sources 
and 102~other sources. Two~different angular thresholds have been chosen for 
the cross-identification: 2$''$ and~4$''$. The~rms concern the difference in the positions,
in arc-seconds, for the cross-identified sources.}\label{table 1}
%\centering
\small
\begin{tabular}{lrrrr}
\hline\hline
Catalog & Threshold  & Defining   & Candidate   & Other   \\
          &  ($''$)       &   ICRF     &    ICRF     & ICRF    \\
\hline 
Quasars  & 4  & 132/212    & 160/294       & 69/102  \\ 
	 &  &   (62.2\%) &    (54.4\%)   &    (67.6\%) \\
    rms ($''$)  $\alpha$/$\delta$       &  & 0.82/0.74  &   0.91/0.75   &   0.69/0.66 \\
BL LAC	  & 4  &  28/212    & 24/294  	   & 11/102     \\ 
 &  &   (13.2\%) &  (8.2\%)      &    (10.7\%) \\
   rms ($''$) $\alpha$/$\delta$          &  & 0.58/0.56  &   0.88/0.55   &  0.86/0.55   \\
Active galaxies  & 4  &  17/212    & 22/294        & 11/102      \\ 
		 &  &   (8.0\%)  &  (7.5\%)      &    (10.7\%)  \\
   rms ($''$) $\alpha$/$\delta$ 	   &  &  0.79/0.66 & 0.93/0.56     & 0.96/0.74  \\
All objects	 & 4  &  177/212   & 206/294        & 91/102      \\ 
rms ($''$)	$\alpha$/$\delta$ 	 &  &  (83.4\%)  &  (70.1\%)      &  (89.2\%)  \\
\hline
Quasars   & 2  & 128/212    & 152/294       & 69/102  \\ 
 &  &   (60.4\%) &    (51.7\%)   &    (67.6\%) \\
 rms ($''$) $\alpha$/$\delta$            &  & 0.74/0.65  &   0.84/0.68   &   0.69/0.66 \\
BL LAC	   	& 2  &  28/212    & 24/294  	   & 11/102     \\ 
		 &  &   (13.2\%) &  (8.2\%)      &    (10.7\%) \\
 rms ($''$) $\alpha$/$\delta$            &  & 0.58/0.56  &   0.88/0.55   &  0.86/0.55   \\
Active galaxies    & 2  &  17/212    & 21/294        & 10/102      \\ 
		   &  &   (8.0\%)  &  (7.1\%)      &    (9.8\%)   \\
 rms ($''$)	$\alpha$/$\delta$ 	   &  &  0.79/0.66 & 0.85/0.67     & 0.59/0.71    \\
All objects	   & 2  &  173/212 & 205/294     & 90/102      \\ 
rms ($''$)	$\alpha$/$\delta$  &  &  (81.6\%)  &  (67.0\%)     &  (88.2\%)  \\
\hline
\end{tabular}
\end{table}