The design of the item is copyrighted, meaning you can't manufacture a product that looks like the original (a knock-off), or is so similar it's obviously derived from the original. The silverplate is pretty much irrelevant, unless it is a unique factor of the design, which is unlikely.
Silver plating processes were once patented, not copyrighted. Some techniques may still be patented, but you wouldn't be able to tell one from another by looking at the product.
Silver filled refers to a metal product made by bonding a layer of silver to a base metal core. The layer of silver is typically thicker than silver plated items, but not as thick as solid silver pieces. This makes silver filled items more affordable than solid silver while still having a higher silver content than plated items.
It means the object is plated with pure silver.
It stands for silver plated which means that the piece of jewelry is covered in a thin layer of silver.
I believe it means double plated silver. Xxx means triple plated.
EPNS stands for electro plated nickel silver. This means that it was made after 1900 and is of no interest to antique collectors. The value is about $20 if you can find a buyer. There are not many buyers for silver plated items.
Gold plated over silver means that there is a layer of gold covering the silver object. While the gold layer is real, the underlying metal is silver. So it is not considered fake, but it is not solid gold either.
18KGP stands for 18 karat gold plated, which means the item is made of a base metal and coated with a thin layer of 18 karat gold. Sterling silver, on the other hand, is a precious metal alloy made of 92.5% silver and 7.5% other metals. Sterling silver is typically more durable and valuable than gold-plated items.
Electro-plated nickel silver
I think it means silver plated
It means the object is plated with pure silver.
Sterling means that an item is solid silver of a certain quality, not plated.
866 means silver plated sorry