Better be careful using the letters RFI as a descriptor or you will learn all about how to prevent Radio Frequency Interference. There have probably been only 3 or 4-million articles in amateur radio publications about RFI to various devices and how to minimize it so it is probably safer to use the full words as was previously posted as in Radio Frequency Identification Systems. Martin McCormick WB5AGZ Stillwater, OK OSU Center for Computing and Information Services Data Communications Group