Russian Silver
Before 1700 there was no systematic control over silver marking and it was only with Peter the Great that a "silver standard" was set and Assay Offices established in all major cities.
The standard for Russian silver is measured in zolotniks: the most common fineness is 84, corresponding to 875/1000 standard. There are also other standards that can be encountered, which include 88, 91, 94 and very rarely 96 (meaning pure silver).