1 Jan 1966 to 31 Dec 1966
US foreign surface letter rate 11 c
Swedish foreign surface letter rate 60 öre
US handstamp shows amount to pay in US cents (normally double deficiency) and US surface letter rate.
In Sweden the indicated fraction multiplied by 60 and rounded up to nearest 5 öre was normally paid by affixing stamps on the item.
Air mail postcard with 8 cent. Correct rate 11
cent. Shortpaid 3 cent. US due handstamp indicates double deficiency 2x3=6
cent and foreign letter rate 11 cent. In Sweden 6/11 of foreign letter
rate 60 öre = 32.73 öre rounded up to 35 öre has been paid
by affixing a postage stamp.