The Defense Department became the first large customer to require suppliers of medical goods to adopt UPNs for their products by July 1 1996. According to Catherine Cahill spokesperson for the Health Industry Manufacturers Assn. (HIMA) other health care providers including at least one state Medicaid program are increasingly requesting similarly labeled packages to aid their handling and tracking of health care products. They have in some cases indicated such products would be given preference. Although bar codes have been used on health care products for some time their use was far from uniform. Cahill said providers want products "source marked" by manufacturers with bar coding as part of the packaging rather than on labels applied by manufacturers distributors or others after the packaging process. Manufacturers may choose one of two primary data structure standards the Uniform Code Council/International Article Number standard (UCC/EAN) or the Health Industry Business Communications Council standard. HIMA advises health care product manufacturers to select a standard based on their market experience and future marketing plans.