A method, a device, and a control system for inputting control information into an appliance, whereby a biometric recognition of a respective user is performed with the aid of a fingerprint. For purposes the method, the corresponding device, and the control system, a user is assigned to one of several user and/or authorization levels by the biometric recognition. A predetermined minimum range of functions and/or range of setting options of the appliance are enabled upon the occurrence of a biometric recognition failure occurs and/or operation by an unknown user.