HOPKINS, Minn. -- Rainbow Foods here, a corporate division of Fleming, has installed electronic shelf labels (ESLs) at three locations in the Minneapolis area. About 20,000 wireless labels have been installed in each store. The wireless technology allows the retailer to transmit prices from the item price database used by a store's point-of-sale system to digital information displays throughout the store. The shelf label solution should help the retailer automate shelf pricing as well as convey promotional messages to shoppers, including special offers, frequent shopper items and nutritional information, according to a source familiar with the situation. The solution is from the NCR Corporation, Dayton, Ohio.