| The date letters below show the background shape for silver. The same letters were used for Gold, which has been marked in Birmingham since 1824, but with a background of a square with cut corners. There may be some variations in backgrounds during the late 19th century, especially on watch cases.
In Birmingham the date letter changes in July up to 1974. From 1975, all Assay offices have the same date letter.
Gold was marked in Birmingham from 1824. The date letters for gold are on the background.
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