The method by which we measure compliance is based on rigorous testing against industry standard specifications. Proximity integrated chip cards (PICCs), i.e passports and proximity coupling devices (PCDs) i.e readers that have been tested and shown to be compliant with the test specifications are subsequently tested against a library of compliant PICCs and PCDs for interoperability. An example procedure, based on analogue and digital testing against an ISO test specification is shown below: