CSN EN IEC 63563-7

CSN EN IEC 63563-7 The Qi Specification, Foreign Object Detection (this document) defines methods for ensuring that the power transfer proceeds without heating metal objects in the magnetic field of a Power Transmitter. Although the Power Transmitter may optionally use any of these methods, some of them require assistance by the Power Receiver.
Original English text of CSN EN Standard.
The price of the Standard included all amendments and correcturs.