| India | Telegraph lines | 1867 Report on Ocean Postal Comunication including discussion about the telegraph lines to India and the extent of the lines in - see part 2 "As regards the Telegraph Service". |
| Advertising | Examples of revenue generating advertisements. | |
| Indigenous | Australia | Telegram from Stan Davey to Prime Minister Harold Holt. |
| Western Australia | Release of a group from Hall's Creek after being charged with making spearheads from insulators. | |
| International labels | Australia | Labels to be affixed to telegrams to show message originated from overseas. |
| Instructional markings | Interuptions to the lines | |
| Interruptions to the lines | Handstamps. | |
Various |
Cockatoos. | |
| Magpies. | ||
| Turkeys. |