| 505 / | HD | SUPERCONDUCTOR TECHNOLOGY: APPARATUS, MATERIAL, PROCESS |
| 825 | DF | APPARATUS, PER SE, DEVICE, PER SE, OR PROCESS OF MAKING OR OPERATING SAME {36} |
| 902 | ![]() | .~ Railway (e.g., rapid transit, etc.): (Class 104) {1} |
| 903 | DF | .~.~> Suspension (e.g., magnetic, electrodynamic, etc.) {5} |