No universal format or interpretation applies to food can expiration codes. The codes allow the manufacturer to track products in interstate commerce and to rotate products as required.
Food can codes potentially consist of open dating, which indicates a "best if used by" date in mm/yyyy format or dd/mm/yyyy format. Other manufacturers use the Julian calendar to express a "best if used by" date, with a three-digit number between one and 365 representing the day of the year and an additional two-digit number representing the "best if used by" year. The numbers 03216, for instance, represents February 1, 2016.
Additional information on food can codes can indicate several things, depending on the manufacturer. The code may give the time of day in army time on which the manufacturer packaged the product and the product number, which varies between products and manufacturers.
Manufacturers list expiration dates on cans to tell consumers when a product begins to diminish in quality and possibly in safety. Spoiled canned goods present the risk of botulism poisoning, which can be fatal. Bulging, leaking or broken can seals and food that is cloudy or odoriferous are telltale signs of spoiled canned goods.
Low-acid canned foods are good indefinitely or at least for two to five years if stored correctly. Canned high-acid foods, such as fruits or tomatoes, have a shelf life of 12 to 18 months.