sheaf(X,M)
If X is the affine variety Spec R, then M should be an R-module. If X is the projective variety Proj R, then M should be a homogeneous R-module.
The source of this document is in /build/reproducible-path/macaulay2-1.25.06+ds/M2/Macaulay2/packages/Varieties/doc-sheaves.m2:181:0.