Descriptor length
| 略名 | 記述子名 | 長さ [bytes] |
| PVD | Primary Volume Descriptor | 512 |
| AVDP | Anchor Volume Descriptor Pointer | 512 |
| VDP | Volume Descriptor Pointer | 512 |
| IUVD | Implementation Use Volume Descriptor | 512 |
| PD | Partition Descriptor | 512 |
| LVD | Logical Volume Descriptor | no max |
| USD | Unallocated Space Descriptor | no max |
| TD | Terminating Descriptor | 512 |
| LVID | Logical Volume Integrity Descriptor | no max |
| FSD | File Set Descriptor | 512 |
| FID | File Identifier Descriptor | 最大論理ブロック長 |
| AED | Allocation Extent Descriptor | 24 |
| IE | Indirect Entry | 52 |
| TE | Terminal Entry | 36 |
| FE | File Entry | 最大論理ブロック長 |
| USE | Unallocated Space Entry | 最大論理ブロック長 |
| SBD | Space Bit Map Descriptor | no max |
| PI | Partition Integrity Entry | N/A |
