Military post offices on the Salolica front. French Aviation Mission with the Serbian army circular marking. Cover with French Unit marking "AVIATION FRANCAISE*DE LARMEE SERBE/PARC SECTEUR 504", fr. with 25c. and posted from "TRESOR ET POSTES*504*23.1.17" with linear French censorship "OUVERT PAR LAUTORITE MILITre", arr. "LEVANTO*9.2.17".