a metal screened electronic labelling system having at least one information bearing electronic coded label including a label coil and an interrogator including a transmitter coil . the system relies on a magnetic field coupling link containing the transmitter coil and the label coil for obtaining information from the label . the coupling link is arranged such that it operates in the near field thereof and substantially none or at most a minority of the magnetic flux which excites the label coil also links the transmitter coil .