Category | Description | Spreading |
| Clearly identified species or populations imported for scientific aims. | Authorized spreading only. |
| Clearly identified species or populations endangered in the wild due to low effectives and/or small distribution area. | Spreading recommended, but members should be priviligied in order to guarantee hybridization avoidance. |
| Clearly identified species or populations, not endangered, and which origin is well-known. | Spreading recommended. Hybridization avoidance should be emphasized. |
| Clearly identified species, but which origin is uncertain. | Normal spreading. Hybridization avoidance should be emphasized. |
| Unkown or probably hybridized species. | Spreading strongly not recommended. |