1918 UNDERPAID MAIL CEYLON TO CHATHAM INCORRECTLY SENT FREE OF CHARGE. Post card from Ceylon (?) to Chatham, Kent posted unpaid and endorsed "On Active Service" with UK "2D/173" charge mark and 2d postage due (damaged) cancelled ROCHESTER CHATHAM 16 OC 18. Mail sent "On Active Service" from a war zone and posted through the Army Post Office was free of charge but this mail was not in that category. (Ref 103926).