NFC or Near Field Communication is a technology used to share data wirelessly through close contact with another compatible device.
Use a NFC compatible phone/tablet/Wii U controller or other device to gain access to the logbook. Some form of internet connection is required (most NFC compatible phones are smart phones anyway) However, It is possible (but less convenient) to access the information by copying the link and looking it up using a computer. The NFC tag will give you the information on how to access the logbook.
To find out if your device is NFC compatible, look in your setting menu, or check here for a list of compatible devices. Sorry Apple users, your device is not on the list.