The current optical identification status of the S5 radio source catalogue.

Optical identifications, magnitudes, and redshifts have been compiled for the 185 radio sources of the S5 catalogue, representing its current optical identification status. Reliable optical counterparts are found for more than 75% of the sources, nearly 50% of which have measured redshifts. Our tabulation also includes radio positions, radio fluxes, and radio spectral indices. References to other catalogues and detailed supplementary notes are given for a large fraction of the sources.