| 340 / | HD | COMMUNICATIONS: ELECTRICAL |
| 853.1 | DF | WELLBORE TELEMETERING OR CONTROL (E.G., SUBSURFACE TOOL GUIDANCE, DATA TRANSFER, ETC.) {14} |
| 854.3 | DF | .~ Using a specific transmission medium (e.g., conductive fluid, annular spacing, etc.) {4} |
| 854.9 | DF | .~.~ Cable or wire (e.g., conductor as support, etc.) {2} |
| 855.2 | ![]() | .~.~.~ Single conductor cable or wire |