| I |
| Ice | 300 |
| Ice Cream & Frozen Desserts-Dealers | 300 |
| Ice Cream Cabinets | 300 |
| Ice Cream Parlors | 300 |
| Ice Making Equipment & Machines | 300 |
| Ice Making Equipment & Machines-Renting | 300 |
| Ice Making Equipment & Machines-Repairing & | 300 |
| Service |
| Ice-Mfrs | 300 |
| Ice-Whsle | 300 |
| Identification Card Service | 300 |
| Identification Equipment & Supplies | 300 |
| Imaging Services | 300 |
| Immigration & Naturalization Consultants | 300 |
| Importers | 305 |
| Importing-General | 305 |
| Incinerators | 305 |
| Incorporating Companies | 305 |
| Industrial Developments | 305 |
| Industrial Equipment & Supplies | 305 |
| Industrial Equipment & Supplies- Repairing & | 305 |
| Service |
| Industrial Equipment & Supplies- Whsle | 305 |
| Industrial Hygiene Consultants | 305 |
| Information Bureaus | 305 |
| Inns | 305 |
| Insect Control Devices | 305 |
| Inspection Bureaus | 305 |
| Insulation Contractors Equipment & Supplies | 306 |
| Insulation Contractors-Cold & Heat | 306 |
| Insulation Materials-Cold & Heat | 306 |
| Insurance | 306 |
| Insurance-Annuities | 321 |
| Insurance-Automobile & Vehicle | 322 |
| Insurance Brokers | 324 |
| Insurance-Bond | 324 |
| Insurance-Burial | 324 |
| Insurance-Business & Commercial | 324 |
| Insurance Consultants | 326 |
| Insurance-Cancer | 326 |
| Insurance-Dental | 326 |
| Insurance-Disability | 326 |
| Insurance-Dump Trucks | 326 |
| Insurance-Fire | 326 |
| Insurance-Flood | 326 |
| Insurance-General | 326 |
| Insurance-Group | 326 |
| Insurance-Health & Accident | 327 |
| Insurance-Homeowners | 328 |
| Insurance-Hospitalization, Medical & Surgical | 329 |
| Plans |
| Insurance-Life | 329 |
| Insurance-Marine | 329 |
| Insurance Underwriters | 330 |
| Insurance-Mobile Homes | 330 |
| Insurance-Mortgage | 330 |
| Insurance-Motorcycle | 330 |
| Insurance-Property & Casualty | 330 |
| Insurance-Renters | 330 |
| Insurance-Title | 330 |
| Insurance-Trucks-Commercial | 330 |
| Insurance-Worker’s Compensation | 330 |
| Intercom Systems & Services | 330 |
| Interior Decorators | 330 |