What does an F mean on silver?

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.

What year is F on silver?

London Date Letter Chart - Online Encyclopedia of Silver Marks, Hallmarks & Makers Marks. to match the shield around the Date Letter Mark. The F was used, 1867 - 1904, in conjunction with a full set of London marks. The second mark was used from 1906.