This is my first post as a new follower and I hope someone can help me. I recently purchased this floral cuff bracelet. It was so dark with tarnish i wasn’t sure it would clean up, and so far only the side bands have started to respond to polishing. Appears to have a repair to one side better seen on the back. It has the initials GRTY on the inside, I have tried to find anything about who this might be but am having no luck. Im hoping that someone can identify the artist either by the initials or by the look of the bracelet. I don’t think it has been worn in a very long time, it was so dark. It is substantially heavy as cuff bracelets go. I appreciate any help!!
Nice bracelet you have there 
my assumption is that this isn’t a hallmark, but rather an inventory number to help the artist know how much they have invested in the piece, or how much they have to charge the buyer.
I had a cuff with some scrawl on the inside, and for years I thought it was a hallmark, until I found this site. When I uploaded my pictures, I learned about how many of these hallmarks are actually artist inventory numbers.
It sounded to me like the consensus was if the mark has three, four or more letters, it tends to be an inventory number. When there are two initials separated by periods, then it’s likely it’s an artist’s initials. There are always exceptions to the rule though!