  We give a general description of the optical observing strategy of the
ROSAT-ESO Flux-Limited X-ray (REFLEX) cluster survey. This presently includes
460 clusters of galaxies selected from the ROSAT All-Sky Survey in the Southern
hemisphere, to a flux limit of 3 10^{-12} erg s^{-1} cm^{-2}. Redshifts are now
measured for 95% of this sample. Work is in progress to complete this coverage,
and then extend the sample to fainter fluxes. A few highlights on the
large-scale distribution of REFLEX clusters and their clustering properties are
also discussed.
