  We clarify the role of gauge invariance for the computation of quantum
non-Gaussian correlators in inflation. A gauge invariant generating functional
for n-point functions is given and the special status of the spatially flat
gauge is pointed out. We also comment on the relation between gauge
transformations, field redefinitions, the choice of $t={\rm const}$
hypersurfaces and the use of boundary terms in computations of non-Gaussianity.
