| G | SK | SECTION G — PHYSICS |
| G08 | KL | SIGNALLING (indicating or display devices per seG09F; transmission of pictures H04N) |
| G08B | UKL | SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS (signalling arrangements on vehicles B60Q, B62D 41/00; railway signalling systems or devices B61L; on cycles B62J 3/00, B62J 6/00; safes or strong-rooms with alarm devices E05G; signalling or alarm devices in mines E21F 17/18; sensitive measuring elements, see the appropriate subclasses of G01; traffic control systems G08G; visual indicating means G09; sound-producing devices G10; radio or near-field calling systems H04B 5/00, H04B 7/00; selecting arrangements H04Q 7/00, H04Q 9/00; loudspeakers, microphones, gramohpone pick-ups or like acoustic electromechanical transducers H04R) |
| G08C | UKL | TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS (fluid pressure transmission systems F15B; sensing members for specific physical variables, see the relevant subclasses, e.g. of G01, of H01; indicators or recorders, see the relevant subclasses, e.g. G01D, G09F; mechanical means for transferring the output of a sensing member into a different variable G01D 5/00; self-balancing bridges G01R; position control in general G05D 3/00; mechanical control systems G05G; systems for transmitting "on/off" signals only, systems for transmitting alarm conditions G08B; order telegraph systems G08B 9/00; generating electric pulses H03K; coding, decoding or code conversion, in general H03M; transmission of digital information H04L; selective calling from one station to another H04Q 9/00) [4] |
| G08G | UKL | TRAFFIC CONTROL SYSTEMS (guiding railway traffic, ensuring the safety of railway traffic B61L; arrangement of road signs or traffic signals E01F 9/00; radar systems or analogous systems, designed for traffic control G01S 13/91; sonar or lidar systems specially designed for traffic control G01S 15/88, G01S 17/88) [2] |