| Issuer | Date | Desc | State | ||
| - | no image | Ecuador | 1/6/1988 | empty sheet (#20798) | incomplete |
| - | no image | Ecuador | 5/29/1988 | empty sheet (#20799) | incomplete |
| - | no image | Ecuador | 7/25/1988 | empty sheet (#20800) | incomplete |
| - | no image | Ecuador | 7/29/1988 | empty sheet (#20801) | incomplete |
| - | no image | Ecuador | 11/24/1988 | empty sheet (#20802) | incomplete |