Radio Frequency Identification (RFID) systems are a technology many libraries use to make materials handling more efficient and to reduce staff workload. If you've never heard of RFID, you may want to start with our RFID Primer which provides a thorough introduction to RFID use in a library context.
While RFID technology has been available for a decades, it has only been used in libraries for the last 10 years or so. The slow uptake in libraries has been because of cost of the technology, concerns about privacy, and the lack of standards.
However, as of March, 2012, NISO finalized a set of recommendations that give libraries what they need to ensure some level of interoperability across RFID implementations in the U.S. If the guidelines are followed, libraries need not be locked into a single RFID vendor's solution and tags from one library can be read by other libraries (and security can be turned on and off as items move across resource-sharing systems). But that's a big IF. It seems that many libraries are not insisting that their RFID vendors follow the NISO guidelines and several vendors are still delivering "solutions" that do not conform to ISO 28560-2, which is what the NISO guidelines call for.
If you are thinking about procuring an RFID system, get current on the standards, and make sure you choose a vendor that supports them.