That is an official stamp certifying that the coin is actually .999 silver. It is verified by an official third party. We started doing this starting from the gold parity coin batch #3 and from then on all gold and silver coins we produce will have this mark.

1 @ 0.014BTC

Viz

dozerz 3 @ 0.003

Current winning bids:

minerjones @ 0.020
minerjones @ 0.020
minerjones @ 0.020
topparkeds @ 0.015
SatoshJr @ 0.014

1 @ 0.017

HmmMAA 3 @ 0.021

Edited , thank you .

Current winning bids:

dozerz @ 0.022
dozerz @ 0.022
HmmMAA @ 0.021
HmmMAA @ 0.021
HmmMAA @ 0.021

1 @ 0.022BTC

Viz