It can mean that it has passed proof testing, could be a maker's mark, could be an inspector mark.
That is a Winchester proof mark.
An optical mark reader can perform this task.
"?" This sign is called a "Question-Mark." It tells the reader that it's a question. For example: What's your favorite color?
pistol bears the famous "ELG Oval" which is the mark of the Liege proof house
Possible French proof mark.
proof mark used in Liege, Belgium
Editor
Depends on what they are. Could be choke markings, proof mark, etc..
I read it. But 'reader' means 'writer'. The Writer is Mark Twain
use it as a wapon
u suck