| Rank | Abbreviation | Meaning |
|---|
| ***** | HCCO | HIPAA (Health Insurance Portability and Accountability Act) Conformance Certification Organization
| |
| ***** | HCCO | Heavy Catalytic Cycle Oil
| |
| ***** | HCCO | Handover Ceremony Co Ordination
| |
| ***** | HCCO | Handover Ceremony Coordination Office
| |
| **** | HCCO | Hwa Chong Chinese Orchestra
| |
| *** | HCCO | Hispanic Chamber of Commerce for Ohio
| |
| *** | HCCO | Humanist Community of Central Ohio
| |
| *** | HCCO | Hunt Club Community Organization
| |
| *** | HCCO | Hill Country Community Orchestra
| |
| *** | HCCO | Health Care Compliance Organization
| |
| ** | HCCO | Hamburg Cocoa Commodity Office
| |
| ** | HCCO | Health Care Compliance Officer
| |
| * | HCCO | Hartford Collaborative for Community Organizing
| |
| * | HCCO | Humboldt Committee for Conscientious Objectors
| |
| * | HCCO | Harris County Council of Organizations
| |
| * | HCCO | Healthy Child Care Ohio
| |
| * | HCCO | Hillingdon Chinese Community Organisation
| |
| * | HCCO | Healthy Child Care Oregon
| |
| * | HCCO | Hospital Corps Clinical Orientation
| |
| * | HCCO | Harari Canadian Community of Ontario
| |
| * | HCCO | Harris County Constable's Office
| |
| * | HCCO | Herzing Career College Ottawa
| |