Some history: '
Certain similarly reference (RIC 99) coins were countermark with a "DV" to downgrade underweight sestertii to the value of dupondii. Claudius was very fair about his coinage and usually ordered these light sestertii to be downgraded to dupondii, so that people got their moneysworth, so to speak. He even permitted many well made counterfeits to remain in circulation, albeit also counterstamped and downgraded to a dupondius or an 'as'.
Don..