| Ref |
country name |
capital |
currencies |
continent |
flag |
| YER | YEMEN (REPÚBLICA DE) on to the stamps | Sanaa 22 Mai 1990 | Rial yéménite (YER) | Asia |  |
| YES | YEMEN PDR on to the stamps | Aden | South Yemeni dinar = 1000 fils | Asia |  |
| YAR | YEMEN REPÚBLICA ÁRABE (YAR) on to the stamps | Sana’a | North Yemini rial = 40 bogaches, North Yemeni rial = 100 fils (from 1978) | Asia |  |
| DJI | YIBUTI on to the stamps | Djibouti | Djiboutian franc = 100 centimes | Africa |  |
| YOU | YUGOSLAVIA on to the stamps | Belgrade | Yugoslav dinar = 100 paras | Europe |  |