| 379 / | HD | TELEPHONIC COMMUNICATIONS |
| 350 | DF | SUPERVISORY OR CONTROL LINE SIGNALLING {5} |
| 352 | DF | .~ Substation originated {8} |
| 355 | ![]() | .~.~ Repertory or abbreviated call signal generation {4} |
| 356 | DF | .~.~.~> With dynamic memory |
| 357 | DF | .~.~.~> Insertable control element or circuitry (e.g., card) |
| 358 | DF | .~.~.~> By motor driven dial rotating device |
| 359 | DF | .~.~.~> Pulse signal generating (e.g., dialing) |