Military post offices on the Salonica front. Registered cover, Serbian registry mark (used in August 1918), fr. with 50c, canc. with "TRESOR ET POSTES*504*14 8 18" with Serbian censorship "PREGLEDALA/VOJNA CENZURA (66)" and posted from "VOJNA POSTA*Br.111*27.7.18" to Weesen.