Martin talks a big ball game about the "business" side of things yet forgot to trademark his name.
There's no rules that apply to that unless you draw the line in the sand yourself by trademarking your name and image. If I named a company Rods n Pistons I can look at Rodandpiston website and I know right off the bat it's worth looking into cause it's different and there's not a conflict of interest. they are not selling services and are not located near where I would be. I would be able to have that name and never have any issues in regards to who's entitled to the name.