This is the flag of the Falkland Islands, used from 1948-1999 (with a short break in April-May 1982 due to the Falklands War). This flag was also used for the en:British Antarctic Territory from 1960-1969 and SGSSI from 1985-1992. The base pattern is from HK Blue Ensign and the arms are from the blue ensign. The FOTW was used for the position of the arms.
No machine-readable source provided. Own work assumed (based on copyright claims).
No machine-readable author provided. Hoshie assumed (based on copyright claims).