  In this short note, we compare the combinatorial sign assignment of
Manolescu, Ozsvath, Szabo and Thurston for grid homology of knots and links in
3-sphere with the sign assignment coming from a coherent system of orientations
on Whitney disks. Although these constructions produce different signs, a small
modification of the convention in either of the two methods results in
identical sign assignments, and thus identical chain complexes.

Geometric Topology