A technology standards project sponsored by the National Association of Convenience Stores (NACS) is developing XML DTDs and schemas to support electronic business document exchange within the convenience store industry. Several pilot projects have been started to test the NAXML specifications for lottery systems, fuel sales, food service transactions, and other retail activities. Version 3.1 of a guidelines document has been produced through the work of the NACS Point of Sale Back Office Task Force: NACS POS/Back Office Interface Guidelines. Common Data Elements and XML Data Interchange. The specification "addresses concerns expressed by the retail community related to the ability to pick back office solutions independently of POS solutions and yet have the two exchange data in an efficient electronic manner. Since early in the standards meetings sponsored by NACS, there has been retailer input and direction regarding their interest in BO/POS integration..." Sample XML DTDs and schemas are available from the web sites. The NACS standards development project is designed to "allow retailers, suppliers, and solution providers to seamlessly exchange financial settlement, ordering, invoicing, and accounting information. The working committees are formalizing models for a range of electronic transactions on general merchandise and supplies, motor fuels, lottery invoicing, and product activity, including general invoicing, purchase orders, credit card reconciliation, electronic fund transfer settlement, and payment remittance." NACS is an international trade association representing 2,300 retail and 1,700 supplier company members.

From the Version 3.0 POS/BO guidelines, "NACS POS/Back Office Interface Guidelines. Common Data Elements and XML Data Interchange." Version 3.0. National Association of Convenience Stores. Draft for Public Comment. January 1, 2001. "This document is the result of concerns expressed by the retail community related to the ability to pick back office solutions independently of POS solutions and yet have the two exchange data in an efficient electronic manner. Since early in the standards meetings sponsored by NACS, there has been retailer input and direction regarding their interest in BO/POS integration. Recognizing the wide array of choices available to retailers for both POS and BO systems, it was determined that a set of data elements which would represent the basic or minimal information required to be passed between the two systems should be established. Any specific implementation will undoubtedly require unique elements to be added to the specification. This version of the Guidelines is designed to offer Point-of-Sale and Back Office solution providers a starting point for discussion regarding the exchange of information between their systems. It provides a common framework, data dictionary, and data interchange mechanism for those common data elements that are likely to be exchanged between provider systems. These Guidelines recommend using the Extensible Markup Language (XML) as a vendor-neutral data exchange medium. Specifically, XML documents are used to transfer data between the disparate Point-of-Sale and Back-Office systems; the content of these documents is defined and constrained by using document type definitions (or DTDs) as defined in XML 1.0..."