IMPORT MARKS

The Custom Act of 1842 ordered that imported gold and silver couldn't be sold in Great Britain and Ireland unless it had been assayed at a British Office.

In 1867 the Foreign Mark was introduced adding an "F" to the appropriate British hallmark.

In 1904 an Act of the Order of Council ordered that foreign silver had to be marked with the decimal value:

.925 for Sterling Standard and .958 for Britannia Standard.

A special Assay Office mark was introduced to be used in the addition to the annual date letter, while the "F" mark was omitted.