| Issuer | Date | Desc | State | ||
| - | no image | Nicaragua | 3/26/1999 | empty sheet (#28095) | incomplete |
| - | no image | Nicaragua | 3/26/1999 | empty sheet (#28096) | incomplete |
| - | no image | Nicaragua | 3/26/1999 | empty sheet (#86092) | incomplete |
| - | no image | Nicaragua | 3/26/1999 | empty sheet (#86093) | incomplete |
| - | no image | Nicaragua | 3/30/1999 | Nature Conservation Campaign, sheet of 9 types | |
| - | no image | Nicaragua | 3/30/1999 | Nature Conservation Campaign, sheet of 9 types | |
| - | no image | Nicaragua | 3/30/1999 | Nature Conservation Campaign, sheet of 9 types | |
| - | no image | Nicaragua | 3/30/1999 | empty sheet (#86094) | incomplete |
| - | no image | Nicaragua | 3/30/1999 | empty sheet (#86095) | incomplete |
| - | no image | Nicaragua | 3/31/1999 | Butterflies 1999, sheet of 9 types | |
| - | no image | Nicaragua | 3/31/1999 | empty sheet (#86096) | incomplete |
| - | no image | Nicaragua | 3/31/1999 | empty sheet (#86097) | incomplete |
| - | no image | Nicaragua | 4/29/1999 | empty sheet (#86098) | incomplete |
| - | no image | Nicaragua | 4/29/1999 | empty sheet (#86099) | incomplete |
| - | no image | Nicaragua | 4/29/1999 | empty sheet (#86100) | incomplete |
| - | no image | Nicaragua | 4/30/1999 | empty sheet (#28101) | incomplete |
| - | no image | Nicaragua | 4/30/1999 | empty sheet (#86101) | incomplete |
| - | no image | Nicaragua | 5/25/1999 | empty sheet (#28102) | incomplete |
| - | no image | Nicaragua | 5/25/1999 | empty sheet (#86102) | incomplete |
| - | no image | Nicaragua | 5/25/1999 | empty sheet (#86103) | incomplete |
| - | no image | Nicaragua | 5/31/1999 | empty sheet (#28103) | incomplete |
| - | no image | Nicaragua | 5/31/1999 | empty sheet (#86075) | incomplete |
| - | no image | Nicaragua | 5/31/1999 | empty sheet (#86076) | incomplete |
| - | no image | Nicaragua | 6/1/1999 | empty sheet (#28104) | incomplete |
| - | no image | Nicaragua | 6/1/1999 | empty sheet (#28105) | incomplete |
| - | no image | Nicaragua | 6/1/1999 | empty sheet (#86077) | incomplete |
| - | no image | Nicaragua | 6/1/1999 | empty sheet (#86078) | incomplete |
| - | no image | Nicaragua | 6/14/1999 | empty sheet (#28106) | incomplete |
| - | no image | Nicaragua | 6/14/1999 | empty sheet (#86079) | incomplete |
| - | no image | Nicaragua | 6/14/1999 | empty sheet (#86080) | incomplete |
| - | no image | Nicaragua | 6/28/1999 | empty sheet (#28107) | incomplete |
| - | no image | Nicaragua | 6/28/1999 | empty sheet (#28108) | incomplete |
| - | no image | Nicaragua | 6/28/1999 | empty sheet (#86081) | incomplete |
| - | no image | Nicaragua | 6/28/1999 | empty sheet (#86082) | incomplete |
| - | no image | Nicaragua | 10/14/1999 | empty sheet (#28109) | incomplete |
| - | no image | Nicaragua | 10/14/1999 | empty sheet (#28110) | incomplete |
| - | no image | Nicaragua | 10/14/1999 | empty sheet (#86083) | incomplete |
| - | no image | Nicaragua | 10/14/1999 | empty sheet (#86084) | incomplete |
| - | no image | Nicaragua | 11/10/1999 | empty sheet (#28111) | incomplete |
| - | no image | Nicaragua | 11/10/1999 | empty sheet (#28112) | incomplete |
| - | no image | Nicaragua | 11/10/1999 | empty sheet (#86085) | incomplete |
| - | no image | Nicaragua | 11/10/1999 | empty sheet (#86086) | incomplete |
| - | no image | Nicaragua | 11/12/1999 | empty sheet (#28113) | incomplete |
| - | no image | Nicaragua | 11/12/1999 | empty sheet (#28114) | incomplete |
| - | no image | Nicaragua | 11/12/1999 | empty sheet (#86087) | incomplete |
| - | no image | Nicaragua | 11/12/1999 | empty sheet (#86088) | incomplete |
| - | no image | Nicaragua | 11/12/1999 | empty sheet (#86089) | incomplete |
| - | no image | Nicaragua | 11/12/1999 | empty sheet (#86090) | incomplete |
| - | no image | Nicaragua | 12/13/1999 | empty sheet (#28115) | incomplete |
| - | no image | Nicaragua | 12/13/1999 | empty sheet (#28116) | incomplete |