  We present a new sample of Parkes half-Jansky flat-spectrum radio sources
having made a particular effort to find any previously unidentified sources.
The sample contains 323 sources selected according to a flux limit of 0.5 Jy at
2.7 GHz, a spectral index measured between 2.7 and 5.0 GHz of alpha > -0.5
(where S(v) is proportional to v to the power of alpha), Galactic latitude
abs(b) > 20 deg and -45 deg < Declination (B1950) < +10 deg. The sample was
selected from a region 3.90 steradians in area.
  We have obtained accurate radio positions for all the unresolved sources in
this sample and combined these with accurate optical positions from digitised
photographic sky survey data to check all the optical identifications. We
report new identifications based on \R- and \Kn-band imaging and new
spectroscopic measurements of many of the sources. We present a catalogue of
the 323 sources of which 321 now have identified optical counterparts and 277
have measured spectral redshifts.
