| 361 / | HD | ELECTRICITY: ELECTRICAL SYSTEMS AND DEVICES |
| 600 | DF | HOUSING OR MOUNTING ASSEMBLIES WITH DIVERSE ELECTRICAL COMPONENTS {11} |
| 679 | DF | .~ For electronic systems and devices {15} |
| 748 | DF | .~.~ Printed circuit board {4} |
| 784 | DF | .~.~.~ Plural {5} |
| 792 | DF | .~.~.~.~ Plural contiguous boards {3} |
| 794 | ![]() | .~.~.~.~.~ Power, voltage, or current layer |