| 455 / | HD | TELECOMMUNICATIONS | 
| 899 | DF | MISCELLANEOUS {5} | 
| FOR 106 | DF | .~ Plural transmitters or receivers (i.e., more than two stations) (455/49.1) {4} | 
| FOR 107 | DF | .~.~ Noise, distortion, or singing reduction (455/50.1) {2} | 
| FOR 110 |  | .~.~.~ Fading compensation (455/52.1) {2} | 
| FOR 111 | DF | .~.~.~.~> Due to weather attenuation (455/52.2) | 
| FOR 112 | DF | .~.~.~.~> Rayleigh or multipath fading (455/52.3) |