Correctly franked letters are very rare. Mainly due to insufficient amount of war tax stamps used in summer and early autumn of 1944...
1944 Šibenik, local provisional issue, registered letter, properly franked with 12,50 kn (3,50 * 3 = 10,50 kn of Šibenik II and 2 kn of NDH definitive), charged with 10 kn war tax, sent from Šibenik (4.IX.44) to Split. Certificate Zrinjšćak.