Allow me to suggest that the scope of your research extend to the wealth of information on this site.
For starters, there is the definition of "hallmark," which can be found on this page: http://www.925-1000.com/silverglossary3.html
The images you have posted, both from the ring and from the Internet source, are a wenyin
is not a maker's mark, not a retailer's mark, and not a manufacturer's mark. And most emphatically, it is not an assay mark or a hallmark. It is not even a silver purity mark declaring a minimum percentage of silver. It is merely a mark that a manufacturer or retailer applied to items with silver content.
A great deal can be learned about CES by reading through past posts on this Forum. For instance, this same wenyin
mark has appeared before, as in this post:viewtopic.php?f=13&t=31908&p=79915&hilit=fine#p79915
Good luck with your research,