 The name change from "in situ" to "operando" for the research field of spectroscopy of catalysts under working conditions was proposed at the Lunteren congress.The analytical principle of measuring the structure, property and function of a material, a component disassembled or as part of a device simultaneously under operation conditions is not restricted to catalysis and catalysts.Batteries and fuel cells have been subject to operando studies with respect to their electrochemical function.