N.Y.C. Admin. Code § 20-587: § 20-587 Sale by true weight or measure required.

It shall be unlawful to sell or offer for sale any commodity or article of merchandise, at or for a greater weight or measure than the true weight or measure thereof; for the purposes of this section the true weight of frozen poultry, shall be the net weight thereof exclusive of any food product or substance added or combined therewith; and all such commodities and articles of merchandise shall be weighed or measured by duly tested devices, sealed and marked by the commissioner or an inspector of the bureau; provided, that vegetables may be sold by the head or bunch.