| Code | Definition | Number of Accessions |
| 1 | DIFFICULT TO REMOVE | 6 |
| 3 | (1 = DIFFICULT TO REMOVE, 9 = EASY TO PICK) | 19 |
| 4 | (1 = DIFFICULT TO REMOVE, 9 = EASY TO PICK) | 8 |
| 5 | (1 = DIFFICULT TO REMOVE, 9 = EASY TO PICK) | 66 |
| 6 | (1 = DIFFICULT TO REMOVE, 9 = EASY TO PICK) | 48 |
| 7 | (1 = DIFFICULT TO REMOVE, 9 = EASY TO PICK) | 27 |
| 8 | (1 = DIFFICULT TO REMOVE, 9 = EASY TO PICK) | 1 |