| WORD | NAME | DESCRIPTION | |
| ISL | Country IDs | Iceland | |
| IND | Country IDs | India | |
| IDN | Country IDs | Indonesia | |
| IRN | Country IDs | Iran | |
| IRQ | Country IDs | Iraq | |
| IRL | Country IDs | Ireland | |
| IMN | Country IDs | Isle of Man | |
| ISR | Country IDs | Israel | |
| ITA | Country IDs | Italy | |
| INSURANCESS | Finance | 3015 - Insurance | Full Description |
| INSURANCE | Finance | 301510 - Insurance | Full Description |
| INSBROKER | Finance | 30151010 - Insurance Brokerage | Full Description |
| INSLIFEHEALTH | Finance | 30151015 - Life and Health Insurance | Full Description |
| INSPROPCAS | Finance | 30151020 - Property and Casualty Insurance | Full Description |
| INSRE | Finance | 30151025 - Reinsurance | Full Description |
| INSDIV | Finance | 30151030 - Diversified Insurance | Full Description |
| INVESTSVCESS | Finance | 3020 - Investment Services | Full Description |
| INVESTSVCE | Finance | 302010 - Investment Services | Full Description |
| INVESTBANK | Finance | 30201015 - Investment Banking and Corporate Finance | Full Description |
| INVESTHOLDING | Finance | 30201020 - Investment Holding Companies | Full Description |
| INVESTDIV | Finance | 30201030 - Diversified Investment | Full Description |
| INFECTIOUS | Healthcare | 35101010 - Infectious Disease Biopharmaceuticals | Full Description |
| IMMUNOLOGY | Healthcare | 35102035 - Immunology Biopharmaceuticals | Full Description |
| INDUSTRIAL | Industrials | 40 - Industrials | Full Description |
| INDMFR | Industrials | 4010 - Industrial Manufacturing | Full Description |
| INDSVCE | Industrials | 4015 - Industrial Services | Full Description |
| INTERMODAL | Industrials | 40151025 - Intermodal/Multimodal Services Since 2022-07-30, previously part of TRAINTRUCKOP | Full Description |
| INDLDIST | Industrials | 401520 - Diversified Industrials Distribution | Full Description |
| INDLDIVDISTRIB | Industrials | 40152020 - Diversified Industrial Distribution | Full Description |
| INFCONSTRSVCE | Industrials | 40152510 - Infrastructure Construction/Contracting Services | Full Description |
| INTERCONNECTMFR | Technology | 55101520 - Interconnect Fabrication | Full Description |
| INTERNET | Technology | 552010 - Internet and Data Services | Full Description |
| INTERNETMEDIA | Technology | 55201015 - Diversified Electronic Media Services | Full Description |
| INTERNETHOSTING | Technology | 55201020 - Internet Hosting Services | Full Description |