25.10.1918 K.u.K Marinefeldpost. Ordinary postcard mailed from S.M.K.D CETINA to Pakrac in Slavonia, Croatia. Very late date 25.10.18 on Marinefeldpostamt Pola cancel. Croatia on 29.10.1918 declared separation from Austro-Hungary and joined short lived State of SHS.
This is the first time I have seen abbreviation S.M.K.D i suppose it means Seiner Majestät Kriegs Dampfer, or His Majesty's War Steamer.
CETINA was commercial steamer that entered service in 1908 . On 14 February 1916 the ship was requisitioned by the K.u.k navy. It served as an Armed escort vessel within Boka Kotorska (Bocche di Cattaro). The ship was transferred to Šibenik on 26 September 1917, and subsequently transferred to the submarine search flotilla in February 1918. It's tonnage was 228t.