Military post offices on the Salonica front. Registered cover fr. with 5c+10c+2x25c. (double weight foreign registered letter rate) and posted from "TRESOR ET POSTES*504*22 9 18" with Serbian censorship canc. "32 PREGLEDALA/VOJNA CENZURA" and French "OUVERT par lAUTORITE*309", "101" and tape "CONTROLE POSTAL MILITAIRE", arr. "ZURICH*29.X.18".