Purchasing power parity (PPP) is an economic theory that states that the exchange rate between two currencies is equal to the ratio of the currencies' respective purchasing power.
MAC Address Generation. Each virtual network adapter in a virtual machine is assigned its own unique MAC address. Each network adapter manufacturer is assigned a unique three-byte prefix called an Organizationally Unique Identifier (OUI), which it can use to generate unique MAC addresses.
Host wire adapters and device wire adapters (Class Code 0xE0, SubClass 0x02) USB serial numbers are optional for all other device classes. However, if you implement the serial-number feature, all devices of the same model must have unique serial numbers. If you implement the serial-number feature, the test setup requires two identical devices that have different serial numbers in order to pass the test.