The key piece of information held on a tag is the electronic product code (EPC,standards for which were developed by the Auto-ID Center). This ‘number plate’ is unique to each tag. The unique number can then be linked to information about the product to which it is attached, for example about when and where the product was made, where its components came from and shelf life details. Some tags may hold this additional information on board however the intention is that most tags will only hold the EPC and additional information will be stored remotely, on a database linked to the management system.