  We study Yukawa unification, including the effects of a physical neutrino
mass consistent with the Superkamiokande observations, in a string/$D$-brane
inspired Pati-Salam model which allows the most general non-universal scalar
and gaugino masses, including the usual $D$-term contributions which arise in
SO(10). We investigate how the tight constraints from rare decays such as $b
\to s \gamma$ and $\tau \to \mu \gamma$ can provide information about the
family dependent supersymmetry breaking soft Lagrangian, for example the
trilinears associated with the second and third family. Many of our results
also apply to SO(10) to which the model approximately reduces in a limiting
case. In both models we find that Yukawa unification is perfectly viable
providing the non-universal soft masses have particular patterns. In this sense
Yukawa unification acts as a window into the soft supersymmetry breaking
Lagrangian.
