  Discrete Fourier analysis on the quasar number count, as a function of
redshift, $z$, calculated from the Sloan Digital Sky Survey DR6 release appears
to indicate that quasars have preferred periodic redshifts with redshift
intervals of 0.258, 0.312, 0.44, 0.63, and 1.1. However the same periods are
found in the mean of the $zConf$ parameter used to flag the reliability of the
spectroscopic measurements. It follows that these redshift periods must result
from some selection effect, as yet undetermined. It does not signal any
intrinsic (quantized) redshifts in the quasars.
