| 178 / | HD | TELEGRAPHY |
|
| 2 R |  | SYSTEMS {21} |
| 3 | DF | .~> Automatic {4} |
| 18.01 | DF | .~> Position coordinate determination for writing (e.g., writing digitizer pad, stylus, or circuitry) {4} |
| 21 | DF | .~> Stenographic |
| 23 R | DF | .~> Printing {8} |
| 43 | DF | .~> Space induction |
| 45 | DF | .~> Loaded circuit {1} |
| 47 | DF | .~> Harmonic or reed {1} |
| 49 | DF | .~> Superposed current |
| 62 | DF | .~> Chemical |
| 63 R | DF | .~> Cable or capacity {6} |
| 64 | DF | .~> Coil transformer |
| 65 | DF | .~> Dynamo |
| 66.1 | DF | .~> Alternating or pulsating current {4} |
| 69 R | DF | .~> Line-clearing and circuit maintenance {12} |
| 69.6 | DF | .~> Call |
| 2 A | DF | .~> Simplex-reversing periodic |
| 2 B | DF | .~> Code changers |
| 2 C | DF | .~> Way stations; party lines |
| 2 D | DF | .~> Round robins |
| 2 E | DF | .~> Satellite |
| 2 F | DF | .~> Coin-controlled, connecting, recording |