Registered envelope Frederiksted 7 October 1915 to New York, USA. 50 BIT King Christian IX tied by CDS “FREDERIKSTED 7/10 1915”, registration mark “Frederiksted / R / 1836” 9. Registration fee 25 BIT, UPU rate 25 BIT from 1.10.1910 – 31.3.1917, correct franking.