Sheets of United Nations, 1998
| Issuer | Date | Desc | State | ||
| - |  |
United Nations | 5/20/1998 | International Year of the Ocean, sheet of 12 types | all added |
| - |  |
United Nations | 6/19/1998 | Rainforest Preservation, sheet of 1 type | all added |
| Issuer | Date | Desc | State | ||
| - | |
United Nations | 5/20/1998 | International Year of the Ocean, sheet of 12 types | all added |
| - | |
United Nations | 6/19/1998 | Rainforest Preservation, sheet of 1 type | all added |