Well, Hermes puts an "S" stamp on any item that they put on sale...it is either an ink mark on the care tag of a scarf or punched into the leather on the inside of a bag or wallet.
A purse that I bought at the Gucci outlet in Italy has an imprint shaped like a circle on the Gucci made in italy tag. My US outlet bag does not have a marking.
it is not consistent in US outlet.. but I have seen they will punch a hole on the tag.. in the outlet.. but I think for gucci store.. they rarely do it.