QSO Catalogue name

For DR3, the catalogues considered for this selection are mostly external, although sources identified by DPAC based on the classification performed by other processing have also been included here.Each catalogue is assigned a <code>catalogue_id</code>.

For DR3 the following applies: <ul> <li> 1: GaiaVariQso2018 (internal DPAC classification based on photometry variability) <li> 2: ICRF2 <li> 3: SDSS-DR12Q <li> 4: LQAC3 <li> 5: Half Million Quasars <li> 6: Secrest+2015 <li> 7: Assef+2018_C75 </ul>Further details on these catalogues are given in the chapter on extended object processing (Section&nbsp;<a href="sec:cu4eo_list">cu4eo_list</a>).</p>