AboutMyCoinWhat do the letters on a coin mean?
A single small letter near the date or on the reverse is the mint mark, and it says which facility struck the coin: D for Denver, S for San Francisco, P or no letter for Philadelphia, W for West Point. Initials elsewhere in the design are the designer’s, and they mean nothing for value.
The mint mark itself
United States coins carry a letter identifying the mint that struck them. D is Denver, S is San Francisco, W is West Point, and P or no letter at all is Philadelphia, which struck most coins without a mark until 1980. Three closed mints appear on older coins: CC for Carson City, O for New Orleans and C or D for the two southern gold mints of the nineteenth century.
The mark exists so the mint could trace a bad batch to the building that made it. It matters to a collector because mintages are reported per mint, and the scarce issue in a series is almost always one mint in one year rather than the year itself.
Where to look for it
The position moved over the life of most series, which is why a general answer is useless and a per-series answer is not. On Washington quarters it sits on the reverse below the eagle until 1964, and on the obverse to the right of the ribbon in the hair from 1968. The position is stated series by series, on the page for the coin in hand.
A coin with no mint mark is not an error and is rarely unusual: it is a Philadelphia coin. The narrow exceptions, where a mark was omitted by accident on a coin that should have had one, are documented per series rather than assumed.
The other letters in the design
The initials tucked into the truncation of the bust or at the base of the design belong to the designer. JF on a Washington quarter is John Flanagan, VDB on a Lincoln cent is Victor David Brenner, AW on a Mercury dime is Adolph Weinman. They appear on every coin of that design and add nothing to the value.
The one famous exception is a matter of position rather than initials: on the cent of 1909 the designer’s initials were placed on the reverse, removed within weeks, and restored to the obverse decades later, which makes the first version a date to check rather than a letter to worry about.
What to do with it
Write down the date and the mint mark together, in that order, because that pair is how every mintage table and every price guide is indexed. A quarter is not a 1964 quarter for pricing purposes; it is a 1964 or a 1964-D, and the tables treat them separately.
Then look the pair up. The Washington quarter pages here list the years and what each is made of, and how much is my coin worth covers what to check after the date and the mark.
Related questions
More on what a coin is worth
Four things set what a coin is worth, and the year stamped on the front is only one of them.
What a Coin Is Worth collects every question on this topic in one place.
Not an appraisal. AboutMyCoin estimates from published specifications and does not authenticate or grade coins.