| 340 / | HD | COMMUNICATIONS: ELECTRICAL |
| 825 | DF | SELECTIVE {23} |
| 825.57 | DF | .~ Pulse responsive actuation {5} |
| 825.62 | ![]() | .~.~ Serial {5} |
| 825.63 | DF | .~.~.~> Pulse width |
| 825.64 | DF | .~.~.~> Pulse spacing (e.g., pulse repetition rate) |
| 825.65 | DF | .~.~.~> Counting {2} |
| 825.68 | DF | .~.~.~> Shift register |
| 825.69 | DF | .~.~.~> Radio link |