Drinkers will soon find out just how good Guinness is for them. Diageo, the world's largest distiller, will disclose alcoholic content and nutritional information per serving for its iconic Irish stout, Smirnoff vodka and Tanqueray gin online and on product packaging as soon as possible, the London-based company said recently. Diageo, which operates in more than 180 countries, is working with regulators globally and has already gained approval for a label on its products in the United States from the Alcohol and Tobacco Tax and Trade Bureau, the company said.