CRACKING THE FOOD-PACKAGE DATE CODE.

Byline: Judith Blake Seattle Times

It's one of shopping's little mysteries: how to decipher the date codes on food packages.

Some codes leave you wondering if you really understand them. Others aren't even meant for shoppers to figure out.

Until date coding becomes more understandable and consistent, here's a guide to some of the dates on packages:

``Closed'' or ``coded'' dating are cryptic numbers and letters stamped on the tops or bottoms of canned or packaged nonperishable foods, telling when and where a product was packed, even down to the production line.

They're called ``closed'' codes because they're intended for the manufacturer's use in restocking store shelves or in case there is a recall. Each company has its own code system.

Because the foods are nonperishable, the dates aren't considered a safety issue for consumers. However, even canned foods can suffer quality loss over time, which would make the pack dates of interest.

Some companies include a clear date in their packing codes. The ``MAR 98'' date on a can of Campbell's Tomato Soup, for instance, refers to two years after the pack date - the last date Campbell's can guarantee top quality for that product, a spokesman said.

He would not translate the rest of the code - 3Y6 CS 0140 1733 - citing such reasons as potential tampering, but said the numbers and letters indicate the production plant and so on.

Though you often can't tell when a nonperishable product was packed, the U.S. Department of Agriculture offers time guidelines for using canned goods for best quality:

Use high-acid canned foods such as tomatoes, grapefruit and pineapple within 12 to 18 months of purchase; low-acid canned foods such as meat, poultry, fish and most vegetables will retain their quality for two to five years, if the can is stored in a cool, dry place and remains in good condition. If the can is bulging or leaking, throw it out.

Open dating codes appear mainly on perishable foods such as meat, poultry, eggs, dairy products and bread, and are meant to be understood by shoppers. They include:

``Sell-by'' date. This tells the store how long to display the product for sale. You should buy the product before the date expires.

``Best-by'' date. ``Best if used by (or before)'' date recommended for best flavor or quality; it is not a safety date. If the date expires during home storage, the USDA says the product still can be safe and of good quality, if properly handled and refrigerated.

``Use-by'' date. This is the last date recommended for use of the product at peak quality.

Expiration date. These dates - for example, ``EXP May 28'' - sometimes appear on egg cartons. This is the last day the store may sell the eggs as fresh. If the expiration date has passed, you should not buy the eggs.

There also are rules about date codes on food products. Knowing them can help you choose fresher, and sometimes safer, foods.

Gaps exist in the dating regulations, but here are some of the key requirements:

Pack dates. Meat, poultry, rabbit or seafood that's cut and packaged in a retail store must show a pack date. If the product later is repackaged by the store, it must retain the original pack date, so the consumer knows how long the item has been in the display case.

The federal government doesn't require wholesale packing plants to put a pack date on fresh meat or poultry, although many plants voluntarily put a date on the outer box.

Pull dates. No pull date is required on fresh meat, poultry or seafood, though many products have them. Pull dates include ``sell-by,'' ``use-by'' and ``freeze-by'' dates.

No pull date is required for refrigerated products, such as meat- or poultry-stuffed pastas, though many have them.

Meat products legally can be sold after the pull date, but they still must be wholesome. Also, they must be separated from other products, and a sign must say, ``Items past pull date.''

Dairy products, breads and deli foods

Perishables. These perishable products must have a pull date on the package, under state regulations. A milk carton, for example, might say, ``Sell by May 26.'' Or there might be just a stamped date, without the words ``sell by.''

MEMO: The Food Marketing Institute, a national association of supermarkets, offers ``The Food Keeper,'' a brochure on selecting, handling and safely storing food. For a copy, send 75 cents and a stamped, self-addresed envelope to Consumer Affairs Department, FMI, 800 Connecticut Ave. NW, Washington, D.C. 20006-2701.