British flag in the 5:8 (7½ft x 12 feet) ratio demanded in Queen's Regulations 1975 (amendment number 37, 2019) for flying at the flag stations specified in Appendix A to Chapter 8, generally on the days specified in the same appendix, namely: Sundays, the monarch's Official Birthday, Coronation Day, Accession Day, Remembrance Sunday, Commonwealth Day, Europe Day (9 May), the birthdays and wedding anniversaries of the senior-most members of the royal family, and on the national patron saints' days within the constituent nation concerned. On other days, most flag stations specified in Queen's Regulations are to fly a smaller flag of different ratio: 4 ft x 6ft (3:2).
Own work based on: Flag of the United Kingdom (3-5).svg:
GPinkerton