Well I guess I don't think of it from a necessity stand point, more from my personal standpoint. For example, if I were lucky enough to get a tattoo by Myke Chambers next year, I would like to have him initial it with 14, not so people would know it was Myke's work but for me as if it were a commissioned painting.
There's no Point, as much as a dislike Myke chambers he does have a distinct enough style that you don't need to get it timestamped or whatever.