Southern Rhodesia 6d aerogramme sent from R.A.F. Heany in March 1953 to Cambrai, France, where it arrived on 14 March 1953.
At the time of posting, the air letter rate to France was 7½d. Hence, the air letter was short-paid 1½ d. Double deficiency (3d) was converted into 10.8 UPU centimes (1d = 3.6 ctms).
The 50 F equivalent - 1,67 times the French UPU letter rate - calculated by the French postal authorities suggests that they have read the taxation as 108 ctms instead of 10.8 ctms.