Product information messages 38 relating to product promotions, sale restrictions of products or products eligible for government subsistence programs, are stored in an EPL additional data file 28 in the memory 24 of an EPL computer 12, together with product information indicators 39 which uniquely identify each product information message 38. When a product information message 38 is to be displayed by an EPL 14 associated with a particular product, a product information indicator corresponding to the message 38 to be displayed is input by an operator to the record for that product in a price look-up (PLU) file 36. A control message addressed to the EPL (14) associated with that product is generated by reading the product information indicator 39 from the PLU file 36 and the corresponding product information message 38 from the EPL additional data file 28. The control message is transmitted to the EPL 14 and the product information message is displayed by a display 22 of the EPL 14. No paper labels, tags or notices need be installed in order to convey the information message to a customer.