I think the shelter I work with found an older dog with a number tattoo and could not trace it. The numbers were clear, yes, but I believe it wasn't registered with any major dog tattoo companies. I don't really see the point, then?
:p My crazedacd account was banned...I'm hoping for technical problems? Haha.. I sent a message via the "Contact Us" link at the bottom but wanted to make sure that was the right thing to do.