  It is noted that the Liang-Zhang correlation can be accounted for with the
viewing angle interpretation proposed earlier. The Ghirlanda correlation,
recently generalized by Nava et al (2006) to a wind profile, can be accounted
for by the viewing angle interpretation accordingly generalized to a wind
profile. Most of the scatter in the spectra and time-integrated brightness in
$\gamma$-ray bursts (GRB) can thus be accounted for by variation in two
parameters, 1) the viewing angle and 2) the jet opening angle, with very little
variation in any other intrinsic parameters. The scatter in apparent isotropic
equivalent fluence and other parameters is reduced by a factor of order 30 when
each of these parameters is considered. Possible difficulties with alternative
explanations are briefly discussed. It is also noted that the relative scatter
in the Amati and Ghirlanda correlations suggests certain conclusions about the
inner engine.
