| 369 / | HD | DYNAMIC INFORMATION STORAGE OR RETRIEVAL |
| 99 | DF | SPECIFIC DETAIL OF INFORMATION HANDLING PORTION OF SYSTEM {4} |
| 127 | DF | .~ Mechanical modification or sensing of storage medium {6} |
| 128 | DF | .~.~ With electrical information signal processing {5} |
| 132 | | .~.~.~ Recording {1} |
| 133 | DF | .~.~.~.~> With transformation or intentional distortion of information signal (e.g., compensation for velocity variation with diameter) |