Look closely at recent supermarket coupons, and you may see some new markings on them near the traditional bar code: sets of neat black bars stacked in two rows.

The new symbols, called GS1 DataBars, can store more data than traditional bar codes , promising new ways for stores to monitor inventory and for customers to save money.

One use of the symbols will be in sophisticated coupon offers that combine deals on multiple products, said Jackie Broberg, who leads coupon control management at General Mills in Minneapolis. A single coupon, for example, could offer discounts on three separate items like eggs, bacon and biscuits, all in one transaction.

Another use of the new symbols is already helping to streamline operations for a common speed bump in the checkout process: loose produce. During the past three years, for example, the Loblaw Companies, the big Canadian supermarket chain, has gradually switched to scannable, miniaturized DataBar labels pasted onto some fruits and vegetables. Instead of entering a 4- or 5-digit number to look up a price, cashiers scan the DataBars on the produce, said Eric Biddiscombe, senior director of planning in Cambridge, Ontario.

"It's quicker and far more accurate," Biddiscombe said. But the system is valuable not only for speeding checkout times and for keeping track of different varieties of bulk vegetables and fruits sold. It also prevents another checkout problem: cashiers mistaking organic vegetables for less expensive, conventionally grown ones, and ringing them up for the lower price.

"The price difference between organic and field tomatoes may be 40 cents a pound or more," he said. "When they aren't rung up as organic, that bites into our profit margins."

Kelly Kirschner, senior marketing manager at Sinclair International, a company in Fresno, Calif., that makes labeling for produce, said DataBars were gradually becoming popular because of limitations of the standard bar code. The standard code, she said, "takes up too much space to be used on loose produce, plus it is for fixed-weight items"--for example, 12-ounce boxes of cereal. The DataBar, by contrast, allows stores to scan for variable weight information.

The labels help stores keep better records, she said. If retailers are receiving Red Delicious apples from three separate suppliers at prices of $8 to $10 a carton, and all the apples are dumped into a single bin, retailers can still tell how many they sold of each lot, as each DataBar is tied to a purchase record.

The next use of DataBars at the supermarket will probably be for goods bought at the delicatessen counter, and for fresh meats and poultry, said Stephen Arens, director, industry development, at GS1 US in Lawrenceville, N.J. GS1 US is the trade organization working to move the DataBar standard forward in the United States. A poultry DataBar, for example, might contain not only the price and product category, but also a sell-by date. If a consumer chose an outdated package, the label would alert the cashier at checkout.

In the future, coupon bar codes will probably be read less from strips of paper, and more from cellphones that people hold out for scanning by the cashier.

Samplesaint, a mobile marketing company in Chicago, for example, has developed technology that lets supermarket scanners pick up the image of a coupon bar code directly from the display on a cellphone. In Samplesaint's system, coupons are sent directly to consumers' cellphones by text message. The coupon's bar code is small enough to fit on the screen of any mobile phone, said Walid Johnson, director of research and development.

Samplesaint erases the coupons from the cellphone after they are scanned at the supermarket, an action that reduces coupon fraud, he said. "Once coupons are used, they can't be forwarded or sent on to anyone else," he said. "We remove them from the phone."

The Samplesaint system will be used this month in a joint trial with Unilever, the consumer products company, at a ShopRite supermarket in Hillsborough, N.J. Consumers can register for coupons from their computer at www.samplesaint.com from their computer or at m.samplesaint.com from their mobile phone Web browser. They can also text from the supermarket to receive a coupon, he said.

In the test, supermarket checkers will be scanning the traditional bar codes. But Samplesaint is prepared to handle the new DataBars, too, when supermarkets are ready. "Our technology can generate the old symbols and the new ones," Johnson said.