| Term | Definition / Meaning / Stand for |
| IC |
Ice Cap |
| ICC |
Ice Core Collection |
| ICD |
Ice Core Drilling |
| ICR |
Ice Core Research |
| ICS |
Ice Core Survey |
| ICT |
Ice Core Technology |
| IGF |
Ice Glacier Formation |
| IGM |
Ice Glacier Monitoring |
| IGP |
Ice Glacier Protection |
| IGR |
Ice Glacier Research |
| IGS |
Ice Glacier Survey |
| IG |
Ice Glacier |
| IB |
Iceberg Basin |
| IBC |
Iceberg Concentration |
| IBF |
Iceberg Formation |
| IBP |
Iceberg Prediction |
| IAF |
Inland Agricultural Fields |
| IAH |
Inland Aquifer Hydrology |
| IAS |
Inland Aquifer Survey |
| IA |
Inland Area |
| ICL |
Inland Coastal Line |
| ICP |
Inland Coastal Plain |
| IDC |
Inland Delta Conservation |
| IDL |
Inland Delta Level |
| IDM |
Inland Delta Management |
| IDP |
Inland Delta Protection |
| IDS |
Inland Delta Study |
| ID |
Inland Delta |
| IED |
Inland Ecosystem Dynamics |
| IEF |
Inland Ecosystem Features |
| IEM |
Inland Ecosystem Management |
| IE |
Inland Ecosystem |
| INE |
Inland Environmental Survey |
| IFF |
Inland Forest Fires |
| IFL |
Inland Forest Level |
| IFM |
Inland Forest Management |
| IFC |
Inland Forestry Control |
| IFS |
Inland Forestry Survey |
| IF |
Inland Forestry |
| IHC |
Inland Hydrology Commission |
| IHL |
Inland Hydrology Level |
| IHM |
Inland Hydrology Monitoring |
| IHP |
Inland Hydrology Program |
| IHR |
Inland Hydrology Research |
| IH |
Inland Hydrology |
| IIS |
Inland Island Survey |
| II |
Inland Island |
| IMA |
Inland Marsh Area |
| IMC |
Inland Marsh Conservation |
| IML |
Inland Marsh Level |
| IMM |
Inland Marsh Management |
| IMP |
Inland Marsh Protection |
| IMS |
Inland Marsh Survey |
| IM |
Inland Marsh |
| INL |
Inland Network Level |
| INM |
Inland Network Management |
| INS |
Inland Network Survey |
| IN |
Inland Network |
| INF |
Inland Nutrient Flow |
| ION |
Inland Ocean Nutrients |
| IOR |
Inland Ocean Research |
| IOS |
Inland Ocean Survey |
| IOD |
Inland Oceanographic Data |
| IOM |
Inland Oceanographic Mapping |
| IO |
Inland Oceanography |
| IPC |
Inland Plain Conservation |
| IPL |
Inland Plain Level |
| IPM |
Inland Plain Management |
| IPP |
Inland Plain Protection |
| IPS |
Inland Plain Survey |