| 379 / | HD | TELEPHONIC COMMUNICATIONS |
| 111 | DF | WITH USAGE MEASUREMENT (E.G., CALL OR TRAFFIC REGISTER) {3} |
| 114 | DF | .~ Call charge metering or monitoring {5} |
| 121 | DF | .~.~ At central office {4} |
| 124 | DF | .~.~.~ Pulse counting or accumulating (e.g., "message metering") {3} |
| 128 | ![]() | .~.~.~.~ Time of day controlled |