| Issuer | Date | Desc | State | ||
| - | no image | Namibia | 1/26/1998 | sheet of 4 types | all added |
| - | no image | Namibia | 3/31/1998 | Diana, Princess of Wales memorial, sheet of 4 types | all added |
| - | no image | Namibia | 4/1/1998 | empty sheet (#32677) | incomplete |
| - | no image | Namibia | 5/14/1998 | sheet of 4 types | all added |
| - | no image | Namibia | 5/18/1998 | Marine Technology, sheet of 1 type | all added |
| - | no image | Namibia | 6/5/1998 | empty sheet (#32680) | incomplete |
| - | no image | Namibia | 6/15/1998 | empty sheet (#32681) | incomplete |
| - | no image | Namibia | 6/18/1998 | empty sheet (#32682) | incomplete |
| - | no image | Namibia | 9/26/1998 | empty sheet (#32683) | incomplete |
| - | no image | Namibia | 10/20/1998 | ILSAPEX '98, sheet of 1 type | |
| - | no image | Namibia | 10/23/1998 | Whales of the Southern Oceans, sheet of 1 type |