The dash-dash-slash-dash ( --\- ) is a signature I started using over a year ago. You'll usually see that symbol hidden somewhere within my images, but what you probably don't know is why I use it.
The symbol came about when I was eating a cookie. I looked at the shape my bottom teeth made when I bit—turned out one tooth was crooked. I liked that pattern enough to use it. But sometimes I forget how to do my signature and have to bite something as a reminder.
Search the symbol in Google and see what happens.
Not very many results at all, huh? It's far more exclusive than "Jonathan Duncan", or even "Jonathan Vair". Eventually, it will only post to my work. My goal of having an unobtrusive and effective signature will then be realized.
It will eventually come in handy when someone posts your work on Tumblr, it gets famous, and the original poster never credits you. And to all the folks on Tumblr, it's graphite, not charcoal. :)