Light rubbing.
The first gold coin with the Mint's designation under the shield of the coat of arms.
Efraim Brenn, head of the Royal Mint in Warsaw, placed his initials on coins for the longest time, as he did so from 1774 until his death in 1792. It was then that the Mint Commission decided to break tradition and start placing the Mint's letters instead of initials. In the case of gold coins, these are M.V. (from Monetaria Varsoviensis).
