| A | Two or more purposes. Use only for objects when no main purpose is identifiable | Sensor screen, image screen |
| B | Conversion of an input variable into a signal intended for further processing | Sensor, microphone, transducer, resistance, video camera, proximity switch, thermal overload relays, motor protection relays, motion detectors, smoke sensors, fire monitors, gas monitors, tachogenerator |
| C | Storage of energy, information, material | Capacitor, hard disk, buffer bater, RAM, ROM buffer, magnetic tape recorder, chip card, floppy, floppy recorder, CD-ROM drive |
| EE | Provision of radiation or heat energy | Incandescent lamps, fluorescent lamps, radiators, annealing furnaces, hot water storage tanks, laser, luminaire, refrigerator |
| F | Direct (automatic) protection of an energy flow or signal flow from undesirable conditions, including equipment for protective purposes. | Fusing fuse, circuit breaker, RCD thermal overload release, surge arrester, Faraday cage, shield, protective device |
| GG | generating an energy flow or material flow or signals used as information carriers. | Generator, battery, pump, fan, fan power supply unit, solar cell, fuel cell, fan, hoists, conveying device |
| K | Processing (reception, processing and provision) of signals or information (but not objects for protective purposes, letter F). | Auxiliary contactor, transistor, time relay, delay element, binary element, regulator, filter, operational amplifier, microporcessor, microcontroller, counter, multiplexer, computer |
| M | Provision of mechanical energy for propulsion | Electric motor, linear motor, internal combustion engine, turbine, solenoid |