Note: There are up to two proposed non-numerical ISBT designations per allele, therefore alleles may appear duplicate in this list
| ISBT name | Designation | Haplotype | Phenotype | Cluster | Structure | First mention | Definitive publication |
| CO*A | standard CO | Colton | Co(a+) Co(b-) Co3+ | main Cluster | CO | 1991 | 1991 |
| CO*B | CO*02 | Colton | Co(b+) Co(a-) Co3+ | main cluster | CO(A45V) | 1994 | 1994 |