Cylindrical-morphology diblock copolymers, when ordered under quiescent conditions, exhibit a 4-fold cloverleaf H-v (depolarized) light scattering pattern, with an off-axis intensity maximum. The grain structure of these samples has been resolved by polarized-light microscopy. Closely-spaced grain pairs, whose optic axes are approximately perpendicular, have been observed. A correlated-grain-pair model is proposed, and scattering patterns are calculated using a correlation function approach. A 4-fold symmetry is a consequence of this model, and for some limited sets of model parameters, a qualitative agreement with experiment is observed.