| 379 / | HD | TELEPHONIC COMMUNICATIONS |
| 90.01 | DF | TELEPHONE LINE OR SYSTEM COMBINED WITH DIVERSE ELECTRICAL SYSTEM OR SIGNALLING (E.G., COMPOSITE) {8} |
| 106.01 | ![]() | .~ Remote indication over telephone line (e.g., telemetry) {4} |
| 106.02 | DF | .~.~> Patient monitoring |
| 106.03 | DF | .~.~> Meter reading {5} |
| 106.09 | DF | .~.~> Ringing suppression |
| 106.11 | DF | .~.~> Interrogation signal |