| 360 / | HD | DYNAMIC MAGNETIC INFORMATION STORAGE OR RETRIEVAL |
| 69 | DF | AUTOMATIC CONTROL OF A RECORDER MECHANISM {3} |
| 75 | DF | .~ Controlling the head {3} |
| 78.01 | ![]() | .~.~ Track changing {2} |
| 78.02 | DF | .~.~.~> Tape {1} |
| 78.04 | DF | .~.~.~> For rotary carrier (e.g., disc) {8} |