Definitions for "Adjustment marks"
File marks found on many pre-19thC coins which have been 'adjusted' (filed down) to the correct weight. It was a worldwide practice which occurred from ancient times until the early 19thC, when new manufacturing techniques made it possible to cut blanks from consistently rolled metal sheets. Excess metal was filed off overweight blanks before the coins were struck to ensure that they were of consistent weight. Sometimes blanks were made deliberately overweight to avoid the more expensive remelting process necessary for underweight coins.
Clipping or filing marks made by the Mint on gold or silver planchets to correct the planchets' weight.
Marks caused by filing a planchet before striking to reduce its weight to the standard, as was sometimes done for early U.S. coinage