Thirteen manufacturers of radio frequency identification (RFID) chips, tags and readers have submitted a unified protocol definition for the technology's next generation of standards. The submission was made to EPCglobal, which is responsible for commercializing electronic product code (EPC) technology that uses RFID to track inventory through the supply chain. The proposal meets the requirements set by Wal-Mart, other retailers and the Department of Defense. According to EPCglobal, the proposal is one of four that is being considered for what is known as the UHF generation 2 protocol. Between now and mid-June, EPCglobal will evaluate the proposals to determine which it will use.