Low frequency catalogues of the CATS database

The authors describe the largest existing publicly accessible radio source database CATS (``astrophysical CATalogues Supporting system''; this http URL). CATS contains more than 300 catalogues of objects detected in different (but mostly radio) wavelength ranges. These include catalogues from the largest existing surveys, like NVSS, FIRST, WENSS, TXS, GB6, IRAS, ROSAT, PGC, MCG, etc. Thus CATS allows to draw samples of objects to study a great variety of astrophysical problems. CATS also includes all of the largest low-frequency catalogues published so far : UTR(10--25 MHz), Culgoora (80, 160 MHz), Cambridge (38, 151, 178 MHz), Miyun (232 MHz), WENSS (325 MHz), Texas (365 MHz), Bologna and Molonglo (408 MHz) etc., and allows the user to operate with them.