 The number after NOM is the distillery number, assigned by the government.NOM does not indicate the location of the distillery, merely the parent company or - in the case where a company leases space in a plant - the physical plant where the tequila was manufactured.NOM-137-SEMARNAT-2003 - Issued on the "Official Gazette" on April 29, 2003, and related to atmospheric pollution, gas desulfurizing plants and sour condensate, and control of emissions of sulfur compounds.