Today a hallmark consists of three compulsory marks ("925" standard mark, assay office mark and sponsors' mark), with two optional voluntary marks (lion passant and date letter).However until 2000 the system had been more or less the same for 450 years.From 1975 the date letter was changed every year on January 1st.The date letter on early spoons (especially trefids) is the most vulnerable to being over-polished due to its position high up the stem towards the terminal.The statute of 1697 which raised the standard of plate silver to Britannia quality also changed makers' marks to the first two letters of his surname.The restoration of Sterling standard in 1719 re-introduced the silversmiths initials as a form of marking.Today there are four assay offices in the UK, although there have been several others over the intervening years.
Today, the metal purity is tested, by taking a scrape from each article and subjecting the scrape to an electronic analysis. The earliest method was by the touch (rubbing the metal on a touch-stone and comparing those rubbings with a sample of known pure silver), a later alternative was by crucible which involves the melting away of all impurities and comparing the resultant weight of pure silver with the weight of the original sample.
Dunstan's Day - the patron saint of silversmiths) of each year.
Hence, an item described as "made in 1750", theoretically could have been made the following year and should really be described as being 1750/51.
Inability to read the date letter will reduce the value of the spoon.
A Statute of 1363 ordained that every master goldsmith (or silversmith) should have his own mark.