Where do you use a FID DEF one Shilling coin?
The one shilling coin (yes, with FID DEF) was a pre-decimal British coin. It was used throughout the UK and some dependencies before the country adopted a decimal currency on 15 February 1971. As the one shilling coin was exactly 1/20th of a pound it was equivalent to 5 new pence and remained in circulation, alongside the new 5p coin till about 1990, when the 10p and 5p coins were drastically reduced in size.
"FID DEF", an abbreviation of "FIDEI DEFENSOR" meaning "Defender of the Faith", is a title given to King Henry VIII, by Pope Leo X for his stance against the Protestant Reformation.
The title has been used by all subsequent British Monarchs and appears in one form or another on all British coins and coins of most of the Commonwealth countries.