Cover from Sidi Abdallah (Maroc) to Salonique BP.28, via "BP.999*5.8.17", arr. "BP.414*7.8.17". Serbian censor cachet "CENSURE MILITAIRE" in Bizerta (Tunisie) and (37) in Salonique. Also censor tape "Controle Postal Militaire Serbe" (type I/rarity R).