It is possible, but is there any specific evidence that is so? I think not. It could just as well be the mark of some merchant named Secundus or any number of other things. Augustan
denarii often bear letters, usually
incuse. They are generally called Bankers' marks, but I do not think anyone really knows very much about them Yous--relief in a rectangle--is unusual, but I do not know of any evidence bearing on its origin or meaning.