| Code | Definition | Number of Accessions |
| 0 | NEEDS_ATTENTION | 3 |
| 1 | FLAT, BACK SLOPING ENOUGH TO DRAIN WATER | 607 |
| 2 | CONCAVE | 200 |
| 3 | CONVEX | 1151 |
| 4 | FLAT, BUT WITH PERIPHERY OF HEAD ROLLED SLIGHTLY, ENOUGH TO COLLECT WATER WHEN HEAD HANGING DOWN | 616 |
| 5 | IRREGULAR | 220 |
| 6 | TRUMPET-SHAPED, USUALLY CONCAVE, AND HAVING A COARSE, HEAVY RECEPT., OFTEN ASSOC. WITH A HOLE IN CENTER OF HEAD | 26 |