(overprint on stamps of Cape of Good Hope): Cape of Good Hope- British occuaption of Vryburg (1899) [Zuid Africaansche Republiek (South African Republic)]
Z.M.
(overprint on stamps of Mexico- Zacatecas): Mexico- Zacatecas: provisionals
Za
(pre-adhesive handstamp): Spanish {SARAGOSSA}
ZA GRUENI KRST
Yugoslavia: postal tax stamps
ZA RDECI KRST
Yugoslavia: postal tax stamps
ZAIRE
Congo (1971-present)
ZANZIBAR
(overprint on stamps of British East Africa): Zanzibar (1895-96)