The option Grading is a matrix that allows one to specify a specific multigrading in which a polynomial map is homogeneous in.
The object Grading is a symbol.
The source of this document is in /build/macaulay2-88fgJW/macaulay2-1.25.11+ds/M2/Macaulay2/packages/MultigradedImplicitization.m2:665:0.