| Comic Books | 132 |
| Communication Service | 132 |
| Communications Consultants | 132 |
| Community Organizations | 132 |
| Compact Discs-New & Used | 132 |
| Compressors-Air & Gas | 132 |
| Compressors-Air & Gas-Mfrs | 132 |
| Compressors-Air & Gas-Repairing | 132 |
| Computer-Dealers | 132 |
| Computer Graphics | 133 |
| Computer Printers-Service & Repair | 133 |
| Computers Networking | 133 |
| Computers-Cable Installation | 133 |
| Computers-On-Line Services | 133 |
| Computers-Renting & Leasing | 133 |
| Computers-Security | 133 |
| Computers-Service & Repair | 133 |
| Computers-Software & Services | 134 |
| Computers-Software & Services-Whsle | 134 |
| Computers-Supplies & Parts | 134 |
| Computers-Support Services | 134 |
| Computers-Systems Designers & Consultants | 135 |
| Computers-Training | 135 |
| Concrete Blocks & Shapes | 135 |
| Concrete Breaking, Cutting, Sawing, Etc | 135 |
| Concrete Construction Forms & Accessories | 135 |
| Concrete Contractors | 135 |
| Concrete Products | 136 |
| Concrete Pumping Service | 136 |
| Concrete Reinforcements | 136 |
| Concrete Repairing, Restoration, Sealing & | 136 |
| Cleaning |
| Concrete-Decorative | 136 |
| Concrete-Ready Mixed | 136 |
| Condiments & Sauces | 136 |
| Condominiums | 136 |
| Condominiums-Maintenance | 137 |
| Conference & Seminar Coordinators | 137 |
| Conference Centers | 137 |
| Conservation Service | 137 |
| Consignment Service | 137 |
| Construction Estimates | 137 |
| Construction Management | 138 |
| Consulates & Other Foreign Government | 138 |
| Representatives |
| Consultants | 138 |
| Contact Lenses | 139 |
| Containerized Freight Service | 139 |
| Contractors Equipment & Supplies-Dealers & | 139 |
| Service |
| Contractors Equipment & Supplies-Renting & | 139 |
| Leasing |
| Contractors-General | 140 |
| Contractors-Oil Field | 144 |
| Controls, Control Systems & Regulators | 144 |
| Convenience Stores | 144 |
| Convention Information Bureaus | 145 |
| Convention Services & Facilities | 145 |
| Convents & Monasteries | 146 |
| Conveyors & Conveying Equipment | 146 |
| Cookies & Crackers | 146 |
| Cooking Instruction | 146 |
| Cooling Towers | 146 |