| 74 / | HD | MACHINE ELEMENT OR MECHANISM |
| 469 | DF | CONTROL LEVER AND LINKAGE SYSTEMS {8} |
| 471 R | DF | .~ Multiple controlled elements {3} |
| 473.1 | DF | .~.~ Transmission control {11} |
| 473.21 | DF | .~.~.~ Restriction of shift, gear selection, or gear engagement {5} |
| 473.24 | | .~.~.~.~ Shift element interlock {2} |
| 473.25 | DF | .~.~.~.~.~> With detent, recess, notch, or groove |
| 473.26 | DF | .~.~.~.~.~> Resiliently biased interlock |