Note: There are up to three proposed ISBT designations per allele, therefore alleles may appear repeatedly in this list
| ISBT name | Designation | Haplotype | Phenotype | Cluster | Structure | First mention | Definitive publication |
| C0*01.01 | standard CO | Colton | Co(a+) Co(b-) Co3+ | main Cluster | CO | 1991 | 1991 |
| CO*01.-04 | CO(Q47R) | Colton | Co:-4 Co(a-) Co(b-) Co3+ | main cluster | CO(Q47R) | 2002 | 2010 |
| CO*01N.03 | CO*01N.03 | Colton | Co(a-) Co(b-) Co:-3 | main cluster | CO(N192K) | 1999 | 1999 |
| CO*01N.04 | CO*01N.04 | Colton | Co:-3 Co(a-) Co(b-) | main cluster | CO(232delG) | 2001 | 2001 |
| CO*01N.05 | CO*01N.05 | Colton | Co(a-) Co(b-) | main cluster | CO(P38S) | 2009 | 2010 |
| CO*01N.06 | CO*01N.06 | Colton | Co(a-) Co(b-) Co:-3 | main cluster | CO(601delG) | 2012 | 2012 |
| CO*02 | CO*02 | Colton | Co(b+) Co(a-) Co3+ | main cluster | CO(A45V) | 1994 | 1994 |
| 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 |
| CO*M.01 | CO*M.01 | Colton | Co3+ weak Co(a-) Co(b-) | main cluster | CO(P38L) | 1994 | 1994 |
| CO*N.01 | CO*N.01 | Colton | Co:-3 Co(a-) Co(b-) | main cluster | CO(del Exon 1) | 1994 | 1994 |