UHF tags can be read at much longer range than the more common HF variety but historically HF tags have been preferred for use in libraries as the long distance reading capability of UHF originally caused major problems when trying to identify individual items (when scanning shelf order for example). Newer UHF scanners now deal with that problem but UHF tags still don’t yet offer the same data storage capabilities as HF.
Like everything else on RFID tags security is managed by data and not by electromagnetism There are two systems in use:
Until recently RFID was limited to being used mainly for circulation(primarily self-service). A data standard should help promote much wider use of the technology to facilitate acquisition and accession, stock management, in-house use monitoring, linking physical to virtual resources and much more.
What you need to know:
Tags dynamically store all the elements used by the RFID system to manage the function being provided (e.g. Self-service circulation, security, acquisition, in-house use monitoring etc.).