| | | |
| GREEK FORCES | |
| GULL FORCE | |
| GURKHA UNITS | |
| GWYDIR REGIMENT | |
H unit names | |
I unit names | |
| ILLAWARRA REGIMENT | |
| IMPERIAL BUSHMEN CORPS | |
| IMPERIAL CAMEL BRIGADE | |
| IMPERIAL CAMEL CORPS | |
| IMPERIAL JAPANESE ARMY | |
| IMPERIAL JAPANESE NAVY | |
| IMPERIAL MOUNTED DIVISION | |
| IMPERIAL WAR GRAVES COMMISSION | |
| IMPERIAL WAR MUSEUM | |
| INDEPENDENT COMPANIES | |
| | NT 1 INDEPENDENT COMPANY | |
| | NT 2/2 INDEPENDENT COMPANY | |
| | NT 2/3 INDEPENDENT COMPANY | |
| | NT 2/4 INDEPENDENT COMPANY | |
| | NT 2/5 INDEPENDENT COMPANY | |
| | NT 2/6 INDEPENDENT COMPANY | |
| | NT 2/7 INDEPENDENT COMPANY | |
| | NT 2/8 INDEPENDENT COMPANY | |
| INDEPENDENT FIELD SQUADRONS | |
| INDI LIGHT HORSE | |
| INDIAN ARMY | |
| INDIAN LABOUR CORPS | |
| INDIAN MULE CORPS | |
| INDIAN NAVY | |