\begin{table}%t1
%\centering
\par
\caption{Contents of the PPM-extended catalogue. }\label{tab_PPMX}
\small \begin{tabular}{rlcl}
\hline\hline
& Label&Units&Explanations\\
\hline
1  &name      &  --    &  Name \\
2  &RAmas      &  mas   &  Right Ascension J2000.0, epoch 2000.0\\
3  &DEmas       & mas   &  Declination J2000.0, epoch 2000.0\\
4  &pmRA        & 0.01~mas/yr & Proper Motion in RA$\cdot$cos(DE)\\
5  &pmDE        & 0.01~mas/yr & Proper Motion in DE\\
6 & $T_{\rm RA}$    &  0.01~yr    &  Mean Epoch (RA) -- 2000.00          \\
7 & $T_{\rm DE}$    & 0.01~yr    &  Mean Epoch (DE) -- 2000.00           \\
8  &$e_{\rm RA}$    & mas   & Mean error of Right Ascension\\
9  &$e_{\rm DE}$    & mas   & Mean error of Declination\\
10 &$e_{\rm pm RA}$  & 0.1~mas/yr &  Mean error of pmRA$\cdot$cos(DE) \\
11 &$e_{\rm pm DE}$  & 0.1~mas/yr &  Mean error of pmDE\\
12 &$G$         & 0.001~mag   &  $G$ magnitude from source catalogue  \\
 &  &			    &   (column 27)  \\
13 &$R_{J}$     & 0.001~mag   & calculated $R_{J}$ magnitude (see text) \\
14 &$B$         & 0.001~mag   & Johnson $B$ magnitude  from ASCC-2.5  \\
15 &$e_B$       & 0.001~mag   &  Standard error of $B$ magnitude\\
16 &$V$         & 0.001~mag   &  Johnson $V$ magnitude  from ASCC-2.5 \\
17 &$e_V$       & 0.001~mag   &  Standard error of $V$ magnitude\\
18 &$J$         & 0.001~mag   &  $J$ magnitude from 2MASS \\
19 &$e_J$       & 0.001~mag   &  Standard error of $J$ magnitude\\
20 &$H$         & 0.001~mag   &  $H$ magnitude from 2MASS \\
21 &$e_H$       & 0.001~mag   &  Standard error of $H$ magnitude\\
22 &$K$         & 0.001~mag   &  $K$ magnitude from 2MASS \\
23 &$e_K$       & 0.001~mag   &  Standard error of $K$ magnitude\\
24 &$n_{\rm obs}$     & --   &  number of observations in the LSQ solution \\
25 &P         & --   &  P flag. Bad LSQ fit\\
26 &sub         & --   &  Subset flag: \\
   &            &       &   ``survey (S)'', \\
   &            &       &    ``additional high-precision stars (H)'' or \\
   &           &       &   ``additional stars (O)''   \\
27 &$I_{\rm sc}$    & --   &  Index of source catalogue\\  
 &  &			    &  H stars from ARIHIP (Wielen et~al.)   \\
&  &			    &  T stars from Tycho-2 (Hoeg et~al.)   \\
&  &			    &  P stars from PPM (R\"oser and Bastian 1991)   \\
&  &			    &  S stars from STARNET (R\"oser 1996)   \\ 
&  &			    &  G stars (matching GSC~1.2 with 2MASS)   \\ 
&  &			    &  A stars (matching AC2000.2 with 2MASS)	\\
28 &Id        & --   &  Identifier in the source catalogue \\
\hline
\end{tabular}
\end{table}