IEC/TR 62152:2009(E) lays the foundation for agreement on the fundamental terms and definitions to be used world wide in describing the transmission properties of a two-port or quadripole end and builds a bridge between the classical quadripole theory and the scattering matrix presentation which is based on incident and reflecting square root of power waves at the input and output of a two-port. This second edition cancels and replaces the previous one and introduces some technical improvements. Important terms and definitions have been added. Some of the terms are better described in the German language and therefore many countries have originally taken terms and definitions from German and translated them into their own language.